---
_id: '64798'
abstract:
- lang: eng
  text: "Lead-containing piezoelectric ceramics are still the base for today’s ultrasonic
    transducers used in broad applications. This is partly due to missing powerful
    lead-free piezoelectric ceramic parts in the commercial market. There has been
    much research on lead-free materials but developing them into marketable parts
    seems to be an ongoing process. The actual exemption of ROHS has expired, but
    as the new exemption has already been requested, ceramic suppliers keep on selling
    lead containing products. Nevertheless, these should be replaced by lead-free
    alternatives for environmental and health issues. \r\nThis contribution focuses
    on exploring the technological readiness level of lead-free hard piezoceramics
    for prestressed ultrasonic transducers. A small series of bolted Langevin transducers
    was set up with standard PZT material and three commercial lead-free variants.
    Results of the building process from individual ring ceramic characteristics to
    transducer load tests are presented. The main finding of this study is that the
    lead-free materials technically can compete with the standard PZT for medium-power
    applications. Some adaptations in the ultrasonic system must be done: the geometry
    must be altered to fit resonance frequency, and higher voltages or thinner ceramics
    are needed to achieve the same vibration level at low load. For reaching same
    power, the volume of lead-free ceramics must be 1.5 to 3 times larger. As already
    promoted in literature, mechanical losses at high vibration levels are smaller
    for the lead-free materials. This might help to argument lead-free piezoelectric
    materials in some applications.\r\n\r\nReferences\r\n1.\tDirective 2011/65/EU
    of the European Parliament and of the Council of 8 June 2011 on the Restriction
    of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment.
    EUR-Lex Document 02011L0065-20240801. Available online: http://data.europa.eu/eli/dir/2011/65/2024-08-01
    (accessed on 24 January 2025).\r\n2.\tLangevin, P. (1918) Method and Apparatus
    for Transmitting and Receiving Submarine Elastic Waves Using the Piezoelectric
    Properties of Quartz. French Patent Office; Patent No. FR505703.\r\n3.\tHemsel,
    T.; Twiefel, J. (2023) Piezoelectric Ultrasonic Power Transducers. In Encyclopedia
    of Materials: Electronics; Academic Press: Oxford, UK; pp. 276–285. https://doi.org/10.1016/b978-0-12-819728-8.00047-4.\r\n4.\tATHENA
    Technologie Beratung GmbH (2025) Description of Ultrasound Generator. Available
    online: http://shop.myathena.de/epages/12074748.sf/de_DE/?ObjectPath=/Shops/12074748/Products/AM200
    (accessed on 13 January 2025).\r\n5.\tLittmann, W.; Hemsel, T.; Kauczor, C.; Wallaschek,
    J.; Sinha, W. (2003) Load-adaptive phase-controller for resonant driven piezoelectric
    devices. Proc. World Congr. Ultrason. 2003, 48, 547–550.\r\n6.\tScheidemann, C.,
    Bornmann, P., Littmann, W., & Hemsel, T. (2025). Lead-Free Ceramics in Prestressed
    Ultrasonic Transducers. Actuators, 14(2), 55. https://doi.org/10.3390/act14020055\r\n"
author:
- first_name: Claus
  full_name: Scheidemann, Claus
  id: '38259'
  last_name: Scheidemann
- first_name: Peter
  full_name: Bornmann, Peter
  last_name: Bornmann
- first_name: Walter
  full_name: Littmann, Walter
  last_name: Littmann
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
citation:
  ama: 'Scheidemann C, Bornmann P, Littmann W, Hemsel T. Bolted Langevin transducers
    with leadfree piezoelectric ceramics. In: ; 2025.'
  apa: Scheidemann, C., Bornmann, P., Littmann, W., &#38; Hemsel, T. (2025). <i>Bolted
    Langevin transducers with leadfree piezoelectric ceramics</i>. International Workshop
    on Piezoelectric Materials and Applications in Actuators (IWPMA), Vilnius, Lithuania.
  bibtex: '@inproceedings{Scheidemann_Bornmann_Littmann_Hemsel_2025, title={Bolted
    Langevin transducers with leadfree piezoelectric ceramics}, author={Scheidemann,
    Claus and Bornmann, Peter and Littmann, Walter and Hemsel, Tobias}, year={2025}
    }'
  chicago: Scheidemann, Claus, Peter Bornmann, Walter Littmann, and Tobias Hemsel.
    “Bolted Langevin Transducers with Leadfree Piezoelectric Ceramics,” 2025.
  ieee: C. Scheidemann, P. Bornmann, W. Littmann, and T. Hemsel, “Bolted Langevin
    transducers with leadfree piezoelectric ceramics,” presented at the International
    Workshop on Piezoelectric Materials and Applications in Actuators (IWPMA), Vilnius,
    Lithuania, 2025.
  mla: Scheidemann, Claus, et al. <i>Bolted Langevin Transducers with Leadfree Piezoelectric
    Ceramics</i>. 2025.
  short: 'C. Scheidemann, P. Bornmann, W. Littmann, T. Hemsel, in: 2025.'
conference:
  end_date: 2025-07-03
  location: Vilnius, Lithuania
  name: International Workshop on Piezoelectric Materials and Applications in Actuators
    (IWPMA)
  start_date: 2025-07-01
date_created: 2026-03-02T10:39:40Z
date_updated: 2026-03-02T11:04:56Z
ddc:
- '620'
department:
- _id: '151'
file:
- access_level: open_access
  content_type: application/pdf
  creator: hemsel
  date_created: 2026-03-02T10:37:46Z
  date_updated: 2026-03-02T11:00:37Z
  file_id: '64799'
  file_name: IWPMA_2025_Hemsel.pdf
  file_size: 1812289
  relation: main_file
file_date_updated: 2026-03-02T11:00:37Z
has_accepted_license: '1'
keyword:
- lead free piezoelectric ceramics
- bolted Langevin transducer
- medium power ultrasound.
language:
- iso: eng
oa: '1'
status: public
title: Bolted Langevin transducers with leadfree piezoelectric ceramics
type: conference
user_id: '210'
year: '2025'
...
---
_id: '64017'
abstract:
- lang: eng
  text: Abstract Donor stabilization of Sn(II) and Pb(II) halides with 1,1?-ferrocenylene
    bridged bisphosphanes has been explored for Fe(C5H4P(C6H5)2)2 (dppf), and Fe(C5H4PH(C4H9))2.
    These bisphosphanes are reacted with SnBr2 and PbCl2 with and without additional
    Lewis acid (AlCl3) forming acyclic and cyclic donor adducts from which the latter
    represent bisphosphoniotetrylenes. Since dynamic exchange in solution is observed,
    characterization includes solution and solid-state NMR in addition to SC-XRD,
    amended by DFT calculations.
author:
- first_name: Sina
  full_name: Nasemann, Sina
  last_name: Nasemann
- first_name: Roman
  full_name: Franz, Roman
  last_name: Franz
- first_name: Denis
  full_name: Kargin, Denis
  last_name: Kargin
- first_name: Clemens
  full_name: Bruhn, Clemens
  last_name: Bruhn
- first_name: Zsolt
  full_name: Kelemen, Zsolt
  last_name: Kelemen
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Rudolf
  full_name: Pietschnig, Rudolf
  last_name: Pietschnig
citation:
  ama: Nasemann S, Franz R, Kargin D, et al. At the limits of bisphosphonio-substituted
    stannylenes. <i>Chemistry - An Asian Journal</i>. 2024;19(8):e202300950. doi:<a
    href="https://doi.org/10.1002/asia.202300950">10.1002/asia.202300950</a>
  apa: Nasemann, S., Franz, R., Kargin, D., Bruhn, C., Kelemen, Z., Gutmann, T., &#38;
    Pietschnig, R. (2024). At the limits of bisphosphonio-substituted stannylenes.
    <i>Chemistry - An Asian Journal</i>, <i>19</i>(8), e202300950. <a href="https://doi.org/10.1002/asia.202300950">https://doi.org/10.1002/asia.202300950</a>
  bibtex: '@article{Nasemann_Franz_Kargin_Bruhn_Kelemen_Gutmann_Pietschnig_2024, title={At
    the limits of bisphosphonio-substituted stannylenes}, volume={19}, DOI={<a href="https://doi.org/10.1002/asia.202300950">10.1002/asia.202300950</a>},
    number={8}, journal={Chemistry - An Asian Journal}, publisher={John Wiley &#38;
    Sons, Ltd}, author={Nasemann, Sina and Franz, Roman and Kargin, Denis and Bruhn,
    Clemens and Kelemen, Zsolt and Gutmann, Torsten and Pietschnig, Rudolf}, year={2024},
    pages={e202300950} }'
  chicago: 'Nasemann, Sina, Roman Franz, Denis Kargin, Clemens Bruhn, Zsolt Kelemen,
    Torsten Gutmann, and Rudolf Pietschnig. “At the Limits of Bisphosphonio-Substituted
    Stannylenes.” <i>Chemistry - An Asian Journal</i> 19, no. 8 (2024): e202300950.
    <a href="https://doi.org/10.1002/asia.202300950">https://doi.org/10.1002/asia.202300950</a>.'
  ieee: 'S. Nasemann <i>et al.</i>, “At the limits of bisphosphonio-substituted stannylenes,”
    <i>Chemistry - An Asian Journal</i>, vol. 19, no. 8, p. e202300950, 2024, doi:
    <a href="https://doi.org/10.1002/asia.202300950">10.1002/asia.202300950</a>.'
  mla: Nasemann, Sina, et al. “At the Limits of Bisphosphonio-Substituted Stannylenes.”
    <i>Chemistry - An Asian Journal</i>, vol. 19, no. 8, John Wiley &#38; Sons, Ltd,
    2024, p. e202300950, doi:<a href="https://doi.org/10.1002/asia.202300950">10.1002/asia.202300950</a>.
  short: S. Nasemann, R. Franz, D. Kargin, C. Bruhn, Z. Kelemen, T. Gutmann, R. Pietschnig,
    Chemistry - An Asian Journal 19 (2024) e202300950.
date_created: 2026-02-07T16:01:49Z
date_updated: 2026-02-17T16:14:49Z
doi: 10.1002/asia.202300950
extern: '1'
intvolume: '        19'
issue: '8'
keyword:
- ferrocene
- lead
- phosphorus
- tetrylene
- tin
language:
- iso: eng
page: e202300950
publication: Chemistry - An Asian Journal
publisher: John Wiley & Sons, Ltd
status: public
title: At the limits of bisphosphonio-substituted stannylenes
type: journal_article
user_id: '100715'
volume: 19
year: '2024'
...
---
_id: '9868'
abstract:
- lang: eng
  text: In order to increase mechanical strength, heat dissipation and ampacity and
    to decrease failure through fatigue fracture, wedge copper wire bonding is being
    introduced as a standard interconnection method for mass production. To achieve
    the same process stability when using copper wire instead of aluminum wire a profound
    understanding of the bonding process is needed. Due to the higher hardness of
    copper compared to aluminum wire it is more difficult to approach the surfaces
    of wire and substrate to a level where van der Waals forces are able to arise
    between atoms. Also, enough friction energy referred to the total contact area
    has to be generated to activate the surfaces. Therefore, a friction model is used
    to simulate the joining process. This model calculates the resulting energy of
    partial areas in the contact surface and provides information about the adhesion
    process of each area. The focus here is on the arising of micro joints in the
    contact area depending on the location in the contact and time. To validate the
    model, different touchdown forces are used to vary the initial contact areas of
    wire and substrate. Additionally, a piezoelectric tri-axial force sensor is built
    up to identify the known phases of pre-deforming, cleaning, adhering and diffusing
    for the real bonding process to map with the model. Test substrates as DBC and
    copper plate are used to show the different formations of a wedge bond connection
    due to hardness and reaction propensity. The experiments were done by using 500
    $\mu$m copper wire and a standard V-groove tool.
author:
- first_name: Simon
  full_name: Althoff, Simon
  last_name: Althoff
- first_name: Jan
  full_name: Neuhaus, Jan
  last_name: Neuhaus
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
- first_name: Walter
  full_name: Sextro, Walter
  id: '21220'
  last_name: Sextro
citation:
  ama: 'Althoff S, Neuhaus J, Hemsel T, Sextro W. Improving the bond quality of copper
    wire bonds using a friction model approach. In: <i>Electronic Components and Technology
    Conference (ECTC), 2014 IEEE 64th</i>. ; 2014:1549-1555. doi:<a href="https://doi.org/10.1109/ECTC.2014.6897500">10.1109/ECTC.2014.6897500</a>'
  apa: Althoff, S., Neuhaus, J., Hemsel, T., &#38; Sextro, W. (2014). Improving the
    bond quality of copper wire bonds using a friction model approach. In <i>Electronic
    Components and Technology Conference (ECTC), 2014 IEEE 64th</i> (pp. 1549–1555).
    <a href="https://doi.org/10.1109/ECTC.2014.6897500">https://doi.org/10.1109/ECTC.2014.6897500</a>
  bibtex: '@inproceedings{Althoff_Neuhaus_Hemsel_Sextro_2014, title={Improving the
    bond quality of copper wire bonds using a friction model approach}, DOI={<a href="https://doi.org/10.1109/ECTC.2014.6897500">10.1109/ECTC.2014.6897500</a>},
    booktitle={Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th},
    author={Althoff, Simon and Neuhaus, Jan and Hemsel, Tobias and Sextro, Walter},
    year={2014}, pages={1549–1555} }'
  chicago: Althoff, Simon, Jan Neuhaus, Tobias Hemsel, and Walter Sextro. “Improving
    the Bond Quality of Copper Wire Bonds Using a Friction Model Approach.” In <i>Electronic
    Components and Technology Conference (ECTC), 2014 IEEE 64th</i>, 1549–55, 2014.
    <a href="https://doi.org/10.1109/ECTC.2014.6897500">https://doi.org/10.1109/ECTC.2014.6897500</a>.
  ieee: S. Althoff, J. Neuhaus, T. Hemsel, and W. Sextro, “Improving the bond quality
    of copper wire bonds using a friction model approach,” in <i>Electronic Components
    and Technology Conference (ECTC), 2014 IEEE 64th</i>, 2014, pp. 1549–1555.
  mla: Althoff, Simon, et al. “Improving the Bond Quality of Copper Wire Bonds Using
    a Friction Model Approach.” <i>Electronic Components and Technology Conference
    (ECTC), 2014 IEEE 64th</i>, 2014, pp. 1549–55, doi:<a href="https://doi.org/10.1109/ECTC.2014.6897500">10.1109/ECTC.2014.6897500</a>.
  short: 'S. Althoff, J. Neuhaus, T. Hemsel, W. Sextro, in: Electronic Components
    and Technology Conference (ECTC), 2014 IEEE 64th, 2014, pp. 1549–1555.'
date_created: 2019-05-20T12:11:44Z
date_updated: 2019-09-16T10:57:58Z
department:
- _id: '151'
doi: 10.1109/ECTC.2014.6897500
keyword:
- adhesion
- circuit reliability
- deformation
- diffusion
- fatigue cracks
- friction
- interconnections
- lead bonding
- van der Waals forces
- Cu
- adhering process
- adhesion process
- ampacity improvement
- bond quality improvement
- cleaning process
- diffusing process
- fatigue fracture failure
- friction energy
- friction model
- heat dissipation
- mechanical strength
- piezoelectric triaxial force sensor
- predeforming process
- size 500 mum
- total contact area
- van der Waals forces
- wedge copper wire bonding
- Bonding
- Copper
- Finite element analysis
- Force
- Friction
- Substrates
- Wires
language:
- iso: eng
page: 1549-1555
publication: Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th
quality_controlled: '1'
status: public
title: Improving the bond quality of copper wire bonds using a friction model approach
type: conference
user_id: '55222'
year: '2014'
...
---
_id: '9878'
abstract:
- lang: eng
  text: (K,Na)NbO3 ceramics have attracted much attention as lead-free piezoelectric
    materials with high piezoelectric properties. High-quality (K,Na)NbO3 ceramics
    can be sintered using KNbO3 and NaNbO3 powders synthesized by a hydrothermal method.
    In this study, to enhance the quality factor of the ceramics, high-power ultrasonic
    irradiation was employed during the hydrothermal method, which led to a reduction
    in the particle size of the resultant powders.
author:
- first_name: G.
  full_name: Isobe, G.
  last_name: Isobe
- first_name: Takafumi
  full_name: Maeda, Takafumi
  last_name: Maeda
- first_name: Peter
  full_name: Bornmann, Peter
  last_name: Bornmann
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
- first_name: Takeshi
  full_name: Morita, Takeshi
  last_name: Morita
citation:
  ama: Isobe G, Maeda T, Bornmann P, Hemsel T, Morita T. Synthesis of lead-free piezoelectric
    powders by ultrasonic-assisted hydrothermal method and properties of sintered
    (K0.48Na0.52)NBO3 ceramics. <i>Ultrasonics, Ferroelectrics, and Frequency Control,
    IEEE Transactions on</i>. 2014;61(2):225-230. doi:<a href="https://doi.org/10.1109/TUFFC.2014.6722608">10.1109/TUFFC.2014.6722608</a>
  apa: Isobe, G., Maeda, T., Bornmann, P., Hemsel, T., &#38; Morita, T. (2014). Synthesis
    of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal method
    and properties of sintered (K0.48Na0.52)NBO3 ceramics. <i>Ultrasonics, Ferroelectrics,
    and Frequency Control, IEEE Transactions On</i>, <i>61</i>(2), 225–230. <a href="https://doi.org/10.1109/TUFFC.2014.6722608">https://doi.org/10.1109/TUFFC.2014.6722608</a>
  bibtex: '@article{Isobe_Maeda_Bornmann_Hemsel_Morita_2014, title={Synthesis of lead-free
    piezoelectric powders by ultrasonic-assisted hydrothermal method and properties
    of sintered (K0.48Na0.52)NBO3 ceramics}, volume={61}, DOI={<a href="https://doi.org/10.1109/TUFFC.2014.6722608">10.1109/TUFFC.2014.6722608</a>},
    number={2}, journal={Ultrasonics, Ferroelectrics, and Frequency Control, IEEE
    Transactions on}, author={Isobe, G. and Maeda, Takafumi and Bornmann, Peter and
    Hemsel, Tobias and Morita, Takeshi}, year={2014}, pages={225–230} }'
  chicago: 'Isobe, G., Takafumi Maeda, Peter Bornmann, Tobias Hemsel, and Takeshi
    Morita. “Synthesis of Lead-Free Piezoelectric Powders by Ultrasonic-Assisted Hydrothermal
    Method and Properties of Sintered (K0.48Na0.52)NBO3 Ceramics.” <i>Ultrasonics,
    Ferroelectrics, and Frequency Control, IEEE Transactions On</i> 61, no. 2 (2014):
    225–30. <a href="https://doi.org/10.1109/TUFFC.2014.6722608">https://doi.org/10.1109/TUFFC.2014.6722608</a>.'
  ieee: G. Isobe, T. Maeda, P. Bornmann, T. Hemsel, and T. Morita, “Synthesis of lead-free
    piezoelectric powders by ultrasonic-assisted hydrothermal method and properties
    of sintered (K0.48Na0.52)NBO3 ceramics,” <i>Ultrasonics, Ferroelectrics, and Frequency
    Control, IEEE Transactions on</i>, vol. 61, no. 2, pp. 225–230, 2014.
  mla: Isobe, G., et al. “Synthesis of Lead-Free Piezoelectric Powders by Ultrasonic-Assisted
    Hydrothermal Method and Properties of Sintered (K0.48Na0.52)NBO3 Ceramics.” <i>Ultrasonics,
    Ferroelectrics, and Frequency Control, IEEE Transactions On</i>, vol. 61, no.
    2, 2014, pp. 225–30, doi:<a href="https://doi.org/10.1109/TUFFC.2014.6722608">10.1109/TUFFC.2014.6722608</a>.
  short: G. Isobe, T. Maeda, P. Bornmann, T. Hemsel, T. Morita, Ultrasonics, Ferroelectrics,
    and Frequency Control, IEEE Transactions On 61 (2014) 225–230.
date_created: 2019-05-20T13:10:14Z
date_updated: 2019-09-16T10:53:17Z
department:
- _id: '151'
doi: 10.1109/TUFFC.2014.6722608
intvolume: '        61'
issue: '2'
keyword:
- Q-factor
- ceramics
- crystal growth from solution
- particle size
- piezoelectric materials
- potassium compounds
- powders
- sintering
- sodium compounds
- ultrasonic effects
- (K0.48Na0.52)NbO3
- KNbO3 powders
- NaNbO3 powders
- high-power ultrasonic irradiation
- lead-free piezoelectric materials
- lead-free piezoelectric powders
- particle size reduction
- piezoelectric properties
- quality factor
- sintered (K0.48Na0.52)NbO3 ceramics
- sintering
- ultrasonic-assisted hydrothermal method
- Acoustics
- Ceramics
- Lead
- Piezoelectric materials
- Powders
- Radiation effects
- Transducers
language:
- iso: eng
page: 225-230
publication: Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions
  on
publication_identifier:
  issn:
  - 0885-3010
quality_controlled: '1'
status: public
title: Synthesis of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal
  method and properties of sintered (K0.48Na0.52)NBO3 ceramics
type: journal_article
user_id: '55222'
volume: 61
year: '2014'
...
---
_id: '9785'
abstract:
- lang: eng
  text: Hydrothermal method enables to synthesize high quality piezoelectric materials.
    To shorten the reaction time and to get higher quality materials, we propose an
    ultrasonic irradiation to the solution during the hydrothermal method. We named
    it ultrasonic assisted hydrothermal method (UAHTM). We have synthesized lead-free
    piezoelectric material and PZT thin film and the effect of UAHTM have been confirmed.
    In this study, we tried to improve UAHTM. First, to generate powerful and stable
    ultrasonic irradiation at high temperature on UAHTM, we developed a new transducer
    using LiNbO3 single crystal. Second, to prevent contamination to the materials,
    A Teflon cover on the tip of transducer was attached.
author:
- first_name: Gaku
  full_name: Isobe, Gaku
  last_name: Isobe
- first_name: Ryo
  full_name: Ageba, Ryo
  last_name: Ageba
- first_name: Takafumi
  full_name: Maeda, Takafumi
  last_name: Maeda
- first_name: Peter
  full_name: Bornmann, Peter
  last_name: Bornmann
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
- first_name: Takeshi
  full_name: Morita, Takeshi
  last_name: Morita
citation:
  ama: 'Isobe G, Ageba R, Maeda T, Bornmann P, Hemsel T, Morita T. Synthesis of piezoelectric
    materials by ultrasonic assisted hydrothermal method. In: B. J. Linde B, Paczkowski
    J, Ponikwicki N, eds. <i>AIP Conference Proceedings</i>. Vol 1433. AIP; 2012:569-572.
    doi:<a href="https://doi.org/10.1063/1.3703251">10.1063/1.3703251</a>'
  apa: Isobe, G., Ageba, R., Maeda, T., Bornmann, P., Hemsel, T., &#38; Morita, T.
    (2012). Synthesis of piezoelectric materials by ultrasonic assisted hydrothermal
    method. In B. B. J. Linde, J. Paczkowski, &#38; N. Ponikwicki (Eds.), <i>AIP Conference
    Proceedings</i> (Vol. 1433, pp. 569–572). AIP. <a href="https://doi.org/10.1063/1.3703251">https://doi.org/10.1063/1.3703251</a>
  bibtex: '@inproceedings{Isobe_Ageba_Maeda_Bornmann_Hemsel_Morita_2012, title={Synthesis
    of piezoelectric materials by ultrasonic assisted hydrothermal method}, volume={1433},
    DOI={<a href="https://doi.org/10.1063/1.3703251">10.1063/1.3703251</a>}, number={1},
    booktitle={AIP Conference Proceedings}, publisher={AIP}, author={Isobe, Gaku and
    Ageba, Ryo and Maeda, Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita,
    Takeshi}, editor={B. J. Linde, Bogumil and Paczkowski, Jacek and Ponikwicki, NikodemEditors},
    year={2012}, pages={569–572} }'
  chicago: Isobe, Gaku, Ryo Ageba, Takafumi Maeda, Peter Bornmann, Tobias Hemsel,
    and Takeshi Morita. “Synthesis of Piezoelectric Materials by Ultrasonic Assisted
    Hydrothermal Method.” In <i>AIP Conference Proceedings</i>, edited by Bogumil
    B. J. Linde, Jacek Paczkowski, and Nikodem Ponikwicki, 1433:569–72. AIP, 2012.
    <a href="https://doi.org/10.1063/1.3703251">https://doi.org/10.1063/1.3703251</a>.
  ieee: G. Isobe, R. Ageba, T. Maeda, P. Bornmann, T. Hemsel, and T. Morita, “Synthesis
    of piezoelectric materials by ultrasonic assisted hydrothermal method,” in <i>AIP
    Conference Proceedings</i>, 2012, vol. 1433, no. 1, pp. 569–572.
  mla: Isobe, Gaku, et al. “Synthesis of Piezoelectric Materials by Ultrasonic Assisted
    Hydrothermal Method.” <i>AIP Conference Proceedings</i>, edited by Bogumil B.
    J. Linde et al., vol. 1433, no. 1, AIP, 2012, pp. 569–72, doi:<a href="https://doi.org/10.1063/1.3703251">10.1063/1.3703251</a>.
  short: 'G. Isobe, R. Ageba, T. Maeda, P. Bornmann, T. Hemsel, T. Morita, in: B.
    B. J. Linde, J. Paczkowski, N. Ponikwicki (Eds.), AIP Conference Proceedings,
    AIP, 2012, pp. 569–572.'
date_created: 2019-05-13T13:21:56Z
date_updated: 2022-01-06T07:04:20Z
department:
- _id: '151'
doi: 10.1063/1.3703251
editor:
- first_name: Bogumil
  full_name: B. J. Linde, Bogumil
  last_name: B. J. Linde
- first_name: Jacek
  full_name: Paczkowski, Jacek
  last_name: Paczkowski
- first_name: Nikodem
  full_name: Ponikwicki, Nikodem
  last_name: Ponikwicki
intvolume: '      1433'
issue: '1'
keyword:
- contamination
- lead compounds
- piezoelectric materials
- piezoelectric thin films
- piezoelectric transducers
- ultrasonic effects
language:
- iso: eng
page: 569-572
publication: AIP Conference Proceedings
publisher: AIP
quality_controlled: '1'
status: public
title: Synthesis of piezoelectric materials by ultrasonic assisted hydrothermal method
type: conference
user_id: '55222'
volume: 1433
year: '2012'
...
---
_id: '9788'
abstract:
- lang: eng
  text: 'A hydrothermal method utilizes a crystallization process in the solution
    so that the pure and high-quality powders can be realized. Sintering from the
    hydrothermal KNbO3 and NaNbO3 powders, a high-dense lead-free piezoelectric (K,Na)NbO3
    ceramics could be obtained (density: 98.8\%). Concerning about the g33 constant,
    high value as large as commercial PZT ceramics was measured. Therefore, the hydrothermal
    (K,Na)NbO3 ceramics is usable for the sensors and the energy harvesting devices.
    To demonstrate the (K,Na)NbO3 ceramics, a hydrophone sensor was fabricated and
    evaluated.'
author:
- first_name: Takafumi
  full_name: Maeda, Takafumi
  last_name: Maeda
- first_name: Peter
  full_name: Bornmann, Peter
  last_name: Bornmann
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
- first_name: Takeshi
  full_name: Morita, Takeshi
  last_name: Morita
citation:
  ama: 'Maeda T, Bornmann P, Hemsel T, Morita T. Piezoelectric applications of hydrothermal
    lead-free (K0.48Na0.52)NbO3 ceramics. In: <i>Ultrasonics Symposium (IUS), 2012
    IEEE International</i>. ; 2012:194-195. doi:<a href="https://doi.org/10.1109/ULTSYM.2012.0048">10.1109/ULTSYM.2012.0048</a>'
  apa: Maeda, T., Bornmann, P., Hemsel, T., &#38; Morita, T. (2012). Piezoelectric
    applications of hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics. In <i>Ultrasonics
    Symposium (IUS), 2012 IEEE International</i> (pp. 194–195). <a href="https://doi.org/10.1109/ULTSYM.2012.0048">https://doi.org/10.1109/ULTSYM.2012.0048</a>
  bibtex: '@inproceedings{Maeda_Bornmann_Hemsel_Morita_2012, title={Piezoelectric
    applications of hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics}, DOI={<a href="https://doi.org/10.1109/ULTSYM.2012.0048">10.1109/ULTSYM.2012.0048</a>},
    booktitle={Ultrasonics Symposium (IUS), 2012 IEEE International}, author={Maeda,
    Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}, year={2012},
    pages={194–195} }'
  chicago: Maeda, Takafumi, Peter Bornmann, Tobias Hemsel, and Takeshi Morita. “Piezoelectric
    Applications of Hydrothermal Lead-Free (K0.48Na0.52)NbO3 Ceramics.” In <i>Ultrasonics
    Symposium (IUS), 2012 IEEE International</i>, 194–95, 2012. <a href="https://doi.org/10.1109/ULTSYM.2012.0048">https://doi.org/10.1109/ULTSYM.2012.0048</a>.
  ieee: T. Maeda, P. Bornmann, T. Hemsel, and T. Morita, “Piezoelectric applications
    of hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics,” in <i>Ultrasonics Symposium
    (IUS), 2012 IEEE International</i>, 2012, pp. 194–195.
  mla: Maeda, Takafumi, et al. “Piezoelectric Applications of Hydrothermal Lead-Free
    (K0.48Na0.52)NbO3 Ceramics.” <i>Ultrasonics Symposium (IUS), 2012 IEEE International</i>,
    2012, pp. 194–95, doi:<a href="https://doi.org/10.1109/ULTSYM.2012.0048">10.1109/ULTSYM.2012.0048</a>.
  short: 'T. Maeda, P. Bornmann, T. Hemsel, T. Morita, in: Ultrasonics Symposium (IUS),
    2012 IEEE International, 2012, pp. 194–195.'
date_created: 2019-05-13T13:28:05Z
date_updated: 2022-01-06T07:04:20Z
department:
- _id: '151'
doi: 10.1109/ULTSYM.2012.0048
keyword:
- crystallisation
- hydrophones
- piezoceramics
- potassium compounds
- powder technology
- powders
- sensors
- sintering
- sodium compounds
- (K0.48Na0.52)NbO3
- KNbO3 powder
- NaNbO3 powder
- crystallization
- energy harvesting devices
- g33 constant
- hydrophone sensor
- hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics
- hydrothermal method
- piezoelectric applications
- sintering
- Materials
- Transducers
language:
- iso: eng
page: 194-195
publication: Ultrasonics Symposium (IUS), 2012 IEEE International
publication_identifier:
  issn:
  - 1948-5719
quality_controlled: '1'
status: public
title: Piezoelectric applications of hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics
type: conference
user_id: '55222'
year: '2012'
...
---
_id: '9743'
abstract:
- lang: eng
  text: The hydrothermal method enables the production of high-quality piezoelectric
    materials. In this study, we propose to irradiate the reaction solutions with
    ultrasonic power during the hydrothermal method to obtain a shorter reaction time
    and a smooth film surface. A high-pressure reaction container for the ultrasonic
    transducer was newly developed, and the ultrasonically-assisted hydrothermal method
    was examined by using this container. The effect of ultrasonic assist on the synthesis
    of lead-zirconate-titanate (PZT) thin films and (K,Na)NbO$_{3}$ powders was verified.
    Thicker PZT film, thickness around 10 ${\mu}$m, could be obtained in one process,
    and (K,Na)NbO$_{3}$ powder was synthesized in half the previous reaction time.
author:
- first_name: Ryo
  full_name: Ageba, Ryo
  last_name: Ageba
- first_name: Yoichi
  full_name: Kadota, Yoichi
  last_name: Kadota
- first_name: Takafumi
  full_name: Maeda, Takafumi
  last_name: Maeda
- first_name: Norihito
  full_name: Takiguchi, Norihito
  last_name: Takiguchi
- first_name: Takeshi
  full_name: Morita, Takeshi
  last_name: Morita
- first_name: Mutsuo
  full_name: Ishikawa, Mutsuo
  last_name: Ishikawa
- first_name: Peter
  full_name: Bornmann, Peter
  last_name: Bornmann
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
citation:
  ama: Ageba R, Kadota Y, Maeda T, et al. Ultrasonically-assisted Hydrothermal Method
    for Ferroelectric Material Synthesis. <i>Journal of Korean Physical Society</i>.
    2010;57(4):918-923. doi:<a href="https://doi.org/10.3938/jkps.57.918">10.3938/jkps.57.918</a>
  apa: Ageba, R., Kadota, Y., Maeda, T., Takiguchi, N., Morita, T., Ishikawa, M.,
    … Hemsel, T. (2010). Ultrasonically-assisted Hydrothermal Method for Ferroelectric
    Material Synthesis. <i>Journal of Korean Physical Society</i>, <i>57</i>(4), 918–923.
    <a href="https://doi.org/10.3938/jkps.57.918">https://doi.org/10.3938/jkps.57.918</a>
  bibtex: '@article{Ageba_Kadota_Maeda_Takiguchi_Morita_Ishikawa_Bornmann_Hemsel_2010,
    title={Ultrasonically-assisted Hydrothermal Method for Ferroelectric Material
    Synthesis}, volume={57}, DOI={<a href="https://doi.org/10.3938/jkps.57.918">10.3938/jkps.57.918</a>},
    number={4}, journal={Journal of Korean Physical Society}, author={Ageba, Ryo and
    Kadota, Yoichi and Maeda, Takafumi and Takiguchi, Norihito and Morita, Takeshi
    and Ishikawa, Mutsuo and Bornmann, Peter and Hemsel, Tobias}, year={2010}, pages={918–923}
    }'
  chicago: 'Ageba, Ryo, Yoichi Kadota, Takafumi Maeda, Norihito Takiguchi, Takeshi
    Morita, Mutsuo Ishikawa, Peter Bornmann, and Tobias Hemsel. “Ultrasonically-Assisted
    Hydrothermal Method for Ferroelectric Material Synthesis.” <i>Journal of Korean
    Physical Society</i> 57, no. 4 (2010): 918–23. <a href="https://doi.org/10.3938/jkps.57.918">https://doi.org/10.3938/jkps.57.918</a>.'
  ieee: R. Ageba <i>et al.</i>, “Ultrasonically-assisted Hydrothermal Method for Ferroelectric
    Material Synthesis,” <i>Journal of Korean Physical Society</i>, vol. 57, no. 4,
    pp. 918–923, 2010.
  mla: Ageba, Ryo, et al. “Ultrasonically-Assisted Hydrothermal Method for Ferroelectric
    Material Synthesis.” <i>Journal of Korean Physical Society</i>, vol. 57, no. 4,
    2010, pp. 918–23, doi:<a href="https://doi.org/10.3938/jkps.57.918">10.3938/jkps.57.918</a>.
  short: R. Ageba, Y. Kadota, T. Maeda, N. Takiguchi, T. Morita, M. Ishikawa, P. Bornmann,
    T. Hemsel, Journal of Korean Physical Society 57 (2010) 918–923.
date_created: 2019-05-13T09:35:33Z
date_updated: 2022-01-06T07:04:19Z
department:
- _id: '151'
doi: 10.3938/jkps.57.918
intvolume: '        57'
issue: '4'
keyword:
- Hydrothermal method
- High-power ultrasonic
- PZT thin film
- Lead-free piezoelectric materials
language:
- iso: eng
page: 918-923
publication: Journal of Korean Physical Society
publication_identifier:
  issn:
  - 1948-5719
quality_controlled: '1'
status: public
title: Ultrasonically-assisted Hydrothermal Method for Ferroelectric Material Synthesis
type: journal_article
user_id: '55222'
volume: 57
year: '2010'
...
---
_id: '9758'
abstract:
- lang: eng
  text: As a lead-free piezoelectric ceramics, (K,Na)NbO$_{3}$ is a promising material
    because of its good piezoelectric properties. In this study, (K$_{1-x}$Na$_{x}$)NbO$_{3}$
    ceramics were synthesized from a KNbO$_{3}$ and NaNbO$_{3}$ mixture powder prepared
    by the hydrothermal reaction. The hydrothermal reaction enables the production
    of high quality powder for the ceramics fabrication process. To obtain (K$_{1-x}$Na$_{x}$)NbO$_{3}$
    ceramics, these two powders KNbO$_{3}$ and NaNbO$_{3}$ were mixed and then sintered
    together. X-Ray diffraction analysis revealed that the solid solution ceramics
    (K$_{1-x}$Na$_{x}$)NbO$_{3}$ was produced by the sintering process. The K/Na ratio
    in (K$_{1-x}$Na$_{x}$)NbO$_{3}$ ceramics was optimized for the best piezoelectric
    properties. The optimized forms was (K$_{0.48}$Na$_{0.52}$)NbO$_{3}$, which showed
    the following piezoelectric properties; k$_{33}$=0.56, d$_{33}$=114pC/N. In addition,
    the ferroelectric properties, P$_{r}$=7.72mC/cm$^{2}$, E$_{c}$=857V/mm, and the
    Curie temperature T$_{c}$=420$_{o}$C were also measured.
author:
- first_name: Takafumi
  full_name: Maeda, Takafumi
  last_name: Maeda
- first_name: Norihito
  full_name: Takiguchi, Norihito
  last_name: Takiguchi
- first_name: Takeshi
  full_name: Morita, Takeshi
  last_name: Morita
- first_name: Mutsuo
  full_name: Ishikawa, Mutsuo
  last_name: Ishikawa
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
citation:
  ama: Maeda T, Takiguchi N, Morita T, Ishikawa M, Hemsel T. Hydrothermal (K1-xNax)NbO3
    Lead-free Piezoelectric Ceramics. <i>Journal of Korean Physical Society</i>. 2010;57(4):924-928.
    doi:<a href="https://doi.org/10.3938/jkps.57.924">10.3938/jkps.57.924</a>
  apa: Maeda, T., Takiguchi, N., Morita, T., Ishikawa, M., &#38; Hemsel, T. (2010).
    Hydrothermal (K1-xNax)NbO3 Lead-free Piezoelectric Ceramics. <i>Journal of Korean
    Physical Society</i>, <i>57</i>(4), 924–928. <a href="https://doi.org/10.3938/jkps.57.924">https://doi.org/10.3938/jkps.57.924</a>
  bibtex: '@article{Maeda_Takiguchi_Morita_Ishikawa_Hemsel_2010, title={Hydrothermal
    (K1-xNax)NbO3 Lead-free Piezoelectric Ceramics}, volume={57}, DOI={<a href="https://doi.org/10.3938/jkps.57.924">10.3938/jkps.57.924</a>},
    number={4}, journal={Journal of Korean Physical Society}, author={Maeda, Takafumi
    and Takiguchi, Norihito and Morita, Takeshi and Ishikawa, Mutsuo and Hemsel, Tobias},
    year={2010}, pages={924–928} }'
  chicago: 'Maeda, Takafumi, Norihito Takiguchi, Takeshi Morita, Mutsuo Ishikawa,
    and Tobias Hemsel. “Hydrothermal (K1-XNax)NbO3 Lead-Free Piezoelectric Ceramics.”
    <i>Journal of Korean Physical Society</i> 57, no. 4 (2010): 924–28. <a href="https://doi.org/10.3938/jkps.57.924">https://doi.org/10.3938/jkps.57.924</a>.'
  ieee: T. Maeda, N. Takiguchi, T. Morita, M. Ishikawa, and T. Hemsel, “Hydrothermal
    (K1-xNax)NbO3 Lead-free Piezoelectric Ceramics,” <i>Journal of Korean Physical
    Society</i>, vol. 57, no. 4, pp. 924–928, 2010.
  mla: Maeda, Takafumi, et al. “Hydrothermal (K1-XNax)NbO3 Lead-Free Piezoelectric
    Ceramics.” <i>Journal of Korean Physical Society</i>, vol. 57, no. 4, 2010, pp.
    924–28, doi:<a href="https://doi.org/10.3938/jkps.57.924">10.3938/jkps.57.924</a>.
  short: T. Maeda, N. Takiguchi, T. Morita, M. Ishikawa, T. Hemsel, Journal of Korean
    Physical Society 57 (2010) 924–928.
date_created: 2019-05-13T10:19:43Z
date_updated: 2022-01-06T07:04:19Z
department:
- _id: '151'
doi: 10.3938/jkps.57.924
intvolume: '        57'
issue: '4'
keyword:
- Lead-free piezoelectric material
- KNN
- Hydrothermal method
language:
- iso: eng
page: 924-928
publication: Journal of Korean Physical Society
publication_identifier:
  issn:
  - 1948-5719
quality_controlled: '1'
status: public
title: Hydrothermal (K1-xNax)NbO3 Lead-free Piezoelectric Ceramics
type: journal_article
user_id: '55222'
volume: 57
year: '2010'
...
---
_id: '9759'
abstract:
- lang: eng
  text: Among various lead-free piezoelectric materials, (K,Na)NbO$_{3}$ is a very
    promising candidate. In this study, (K,Na)NbO$_{3}$ ceramics were sintered from
    mixed (K,Na)NbO$_{3}$ and NaNbO$_{3}$ powders prepared by hydrothermal reaction.
    These two powders were mixed with distilled water in a KNbO$_{3}$/NaNbO$_{3}$
    molar ratio of 1. After sintering the mixed powder, the solid solution of (Na,K)NbO$_{3}$
    ceramics was obtained. The electrical properties such as the electromechanical
    coupling factors k$_{p}$ and k$_{33}$, the mechanical quality factor, Q$_{m}$,
    and the piezoelectric constant d$_{33}$ of the sintered (K,Na)NbO$_{3}$ ceramics
    were 0.32, 0.48, 71 (radial mode), 118 ((33)mode), and 107 pC/N, respectively.
author:
- first_name: Takafumi
  full_name: Maeda, Takafumi
  last_name: Maeda
- first_name: Norihito
  full_name: Takiguchi, Norihito
  last_name: Takiguchi
- first_name: Takeshi
  full_name: Morita, Takeshi
  last_name: Morita
- first_name: Mutsuo
  full_name: Ishikawa, Mutsuo
  last_name: Ishikawa
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
citation:
  ama: Maeda T, Takiguchi N, Morita T, Ishikawa M, Hemsel T. (K,Na)NbO3 lead-free
    piezoelectric ceramics synthesized from hydrothermal powders. <i>Materials Letters</i>.
    2010;64(2):125-128. doi:<a href="https://doi.org/10.1016/j.matlet.2009.10.012">10.1016/j.matlet.2009.10.012</a>
  apa: Maeda, T., Takiguchi, N., Morita, T., Ishikawa, M., &#38; Hemsel, T. (2010).
    (K,Na)NbO3 lead-free piezoelectric ceramics synthesized from hydrothermal powders.
    <i>Materials Letters</i>, <i>64</i>(2), 125–128. <a href="https://doi.org/10.1016/j.matlet.2009.10.012">https://doi.org/10.1016/j.matlet.2009.10.012</a>
  bibtex: '@article{Maeda_Takiguchi_Morita_Ishikawa_Hemsel_2010, title={(K,Na)NbO3
    lead-free piezoelectric ceramics synthesized from hydrothermal powders}, volume={64},
    DOI={<a href="https://doi.org/10.1016/j.matlet.2009.10.012">10.1016/j.matlet.2009.10.012</a>},
    number={2}, journal={Materials Letters}, author={Maeda, Takafumi and Takiguchi,
    Norihito and Morita, Takeshi and Ishikawa, Mutsuo and Hemsel, Tobias}, year={2010},
    pages={125–128} }'
  chicago: 'Maeda, Takafumi, Norihito Takiguchi, Takeshi Morita, Mutsuo Ishikawa,
    and Tobias Hemsel. “(K,Na)NbO3 Lead-Free Piezoelectric Ceramics Synthesized from
    Hydrothermal Powders.” <i>Materials Letters</i> 64, no. 2 (2010): 125–28. <a href="https://doi.org/10.1016/j.matlet.2009.10.012">https://doi.org/10.1016/j.matlet.2009.10.012</a>.'
  ieee: T. Maeda, N. Takiguchi, T. Morita, M. Ishikawa, and T. Hemsel, “(K,Na)NbO3
    lead-free piezoelectric ceramics synthesized from hydrothermal powders,” <i>Materials
    Letters</i>, vol. 64, no. 2, pp. 125–128, 2010.
  mla: Maeda, Takafumi, et al. “(K,Na)NbO3 Lead-Free Piezoelectric Ceramics Synthesized
    from Hydrothermal Powders.” <i>Materials Letters</i>, vol. 64, no. 2, 2010, pp.
    125–28, doi:<a href="https://doi.org/10.1016/j.matlet.2009.10.012">10.1016/j.matlet.2009.10.012</a>.
  short: T. Maeda, N. Takiguchi, T. Morita, M. Ishikawa, T. Hemsel, Materials Letters
    64 (2010) 125–128.
date_created: 2019-05-13T10:21:17Z
date_updated: 2022-01-06T07:04:19Z
department:
- _id: '151'
doi: 10.1016/j.matlet.2009.10.012
intvolume: '        64'
issue: '2'
keyword:
- Lead-free piezoelectric material
- (K
- Na)NbO$_{3}$ ceramics
- Sintering solid solution
- Piezoelectric properties
language:
- iso: eng
page: 125-128
publication: Materials Letters
publication_identifier:
  issn:
  - 1948-5719
quality_controlled: '1'
status: public
title: (K,Na)NbO3 lead-free piezoelectric ceramics synthesized from hydrothermal powders
type: journal_article
user_id: '55222'
volume: 64
year: '2010'
...