@article{47996, abstract = {{Specific heat capacity measurements by differential scanning calorimetry (DSC) of single crystals of solid solutions of LiNbO3 and LiTaO3 are reported and compared with corresponding ab initio calculations, with the aim to investigate the variation of the ferroelectric Curie temperature as a function of composition. For this purpose, single crystals of these solid solutions were grown with Czochralski pulling along the c-axis. Elemental composition of Nb and Ta was investigated using XRF analysis, and small samples with homogeneous and well known composition were used for the DSC measurements. We observed that the ferroelectric Curie temperature decreases linearly with increasing Ta concentration in the LiNb1−x Tax O3 solid solution crystals. Furthermore, the ferroelectric transition width of a mixed crystal appears to be smaller, as compared to pure LiTaO3.}}, author = {{Bashir, Umar and Böttcher, Klaus and Klimm, Detlef and Ganschow, Steffen and Bernhardt, Felix and Sanna, Simone and Rüsing, Michael and Eng, Lukas M. and Bickermann, Matthias}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, keywords = {{Condensed Matter Physics, Electronic, Optical and Magnetic Materials}}, number = {{1}}, pages = {{250--262}}, publisher = {{Informa UK Limited}}, title = {{{Solid solutions of lithium niobate and lithium tantalate: crystal growth and the ferroelectric transition}}}, doi = {{10.1080/00150193.2023.2189842}}, volume = {{613}}, year = {{2023}}, } @article{13519, author = {{Riefer, A. and Sanna, S. and Schmidt, Wolf Gero}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, pages = {{78--85}}, title = {{{LiNb1-xTaxO3Electronic Structure and Optical Response fromFirst-PrinciplesCalculations}}}, doi = {{10.1080/00150193.2013.821904}}, volume = {{447}}, year = {{2013}}, } @article{13819, author = {{Riefer, A. and Sanna, S. and Schmidt, Wolf Gero}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, pages = {{78--85}}, title = {{{LiNb1-xTaxO3Electronic Structure and Optical Response fromFirst-PrinciplesCalculations}}}, doi = {{10.1080/00150193.2013.821904}}, volume = {{447}}, year = {{2013}}, } @article{13520, abstract = {{Atomistic simulations in the framework of the density functional theory have been used to model morphologic and vibrational properties of lithium niobate–lithium tantalate mixed crystals as a function of the [Nb]/[Ta] ratio. Structural parameters such as the crystal volume and the lattice parameters a and c vary roughly linearly from LiTaO3 to LiNbO3, showing only minor deviations from the Vegard behavior. Our ab initio calculations demonstrate that the TO1, TO2 and TO4 vibrational modes become harder with increasing Nb concentration. TO3 becomes softer with increasing Nb content, instead. Furthermore, the investigated zone center A1 -TO phonon modes are characterized by a pronounced stoichiometry dependence. Frequency shifts as large as 30 cm−1 are expected as the [Nb]/[Ta] ratio grows from 0 to 1. Therefore, spectroscopic techniques sensitive to the A1 modes (such as Raman spectroscopy), can be employed for a direct and non-destructive determination of the crystal composition.}}, author = {{Sanna, Simone and Riefer, A. and Neufeld, Sergej and Schmidt, Wolf Gero and Berth, Gerhard and Rüsing, Michael and Widhalm, A. and Zrenner, Artur}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, keywords = {{Ferroelectrics, vibrational properties, LiNbO3, LiTaO3, mixed crystals}}, number = {{1}}, pages = {{63--68}}, title = {{{Vibrational Fingerprints of LiNbO3-LiTaO3Mixed Crystals}}}, doi = {{10.1080/00150193.2013.821893}}, volume = {{447}}, year = {{2013}}, } @article{4377, abstract = {{Confocal Raman spectroscopy was performed as an archetype imaging method to study the ferroelectric domain structure of periodically poled lithium niobate. More precisely, the linkage out of spatial resolution and spectral information proved itself as very useful. Here a specific modulation of the Raman lines by the local variation of polarity and a non-symmetric measuring-signal across the domain structure were found, which allows for imaging of domain boundaries as well as oppositely orientated domains. The high potential of this method is demonstrated by the visualization of the ferroelectric domain structures based on various phonon modes.}}, author = {{Berth, Gerhard and Hahn, Wjatscheslaw and Wiedemeier, Volker and Zrenner, Artur and Sanna, Simone and Schmidt, Wolf Gero}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, keywords = {{Raman spectroscopy, ferroelectric domains, LiNbO3, confocal imaging}}, number = {{1}}, pages = {{44--48}}, publisher = {{Informa UK Limited}}, title = {{{Imaging of the Ferroelectric Domain Structures by Confocal Raman Spectroscopy}}}, doi = {{10.1080/00150193.2011.594774}}, volume = {{420}}, year = {{2011}}, } @article{13561, author = {{Berth, Gerhard and Hahn, Wjatscheslaw and Wiedemeier, Volker and Zrenner, Artur and Sanna, Simone and Schmidt, Wolf Gero}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, pages = {{44--48}}, title = {{{Imaging of the Ferroelectric Domain Structures by Confocal Raman Spectroscopy}}}, doi = {{10.1080/00150193.2011.594774}}, volume = {{420}}, year = {{2011}}, } @article{4543, abstract = {{The vibrational properties of the LiNbO3 (0001) surfaces have been investigated both from first principles and with Raman spectroscopy measurements. Firstly, the phonon modes of bulk and of the (0001) surface are calculated by means of the density functional theory. Our calculations reveal the existence of localised vibrational modes both at the positive and at the negative surface. The surface vibrations are found at energies above and within the bulk bands. Phonon modes localised at the positive and at the negative surface differ substantially. In a second step, the Raman spectra of LiNbO3 bulk and of the two surfaces have been measured. Raman spectroscopy is shown to be sensitive to differences between bulk and surface and between positive and negative surface. The calculated and measured frequencies are in agreement within the error of the method.}}, author = {{Sanna, S. and Berth, Gerhard and Hahn, W. and Widhalm, A. and Zrenner, Artur and Schmidt, Wolf Gero}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, number = {{1}}, pages = {{1--8}}, publisher = {{Informa UK Limited}}, title = {{{Localised Phonon Modes at LiNbO3(0001) Surfaces}}}, doi = {{10.1080/00150193.2011.594396}}, volume = {{419}}, year = {{2011}}, } @article{39741, author = {{Kitzerow, Heinz-Siegfried}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, keywords = {{Condensed Matter Physics, Electronic, Optical and Magnetic Materials}}, number = {{1}}, pages = {{66--85}}, publisher = {{Informa UK Limited}}, title = {{{Blue Phases: Prior Art, Potential Polar Effects, Challenges}}}, doi = {{10.1080/00150191003683807}}, volume = {{395}}, year = {{2010}}, } @article{40082, author = {{Kitzerow, Heinz-Siegfried}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, keywords = {{Condensed Matter Physics, Electronic, Optical and Magnetic Materials}}, number = {{1}}, pages = {{66--85}}, publisher = {{Informa UK Limited}}, title = {{{Blue Phases: Prior Art, Potential Polar Effects, Challenges}}}, doi = {{10.1080/00150191003683807}}, volume = {{395}}, year = {{2010}}, } @article{4553, abstract = {{We present results on ferroelectric micro-domains obtained by confocal second harmonic microscopy. The high potential of this technique is demonstrated by imaging periodic ferroelectric domain structures in the surface of planar X-cut lithium niobate (LN) and in the body of ridges fabricated by plasma etching on X-cut LN as well. In both cases the measured second harmonic signal reveals a strong contrast between inverted and non-inverted domain sections. This enabled a depth-resolved non-destructive tomography of micro-domains in ridge structures in all three dimensions.}}, author = {{Berth, Gerhard and Wiedemeier, Volker and Hüsch, Klaus-Peter and Gui, Li and Hu, Hui and Sohler, Wolfgang and Zrenner, Artur}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, keywords = {{Nonlinear microscopy, ferroelectric micro-domains, confocal imaging, LiNbO3}}, number = {{1}}, pages = {{132--141}}, publisher = {{Informa UK Limited}}, title = {{{Imaging of Ferroelectric Micro-Domains in X-Cut Lithium Niobate by Confocal Second Harmonic Microscopy}}}, doi = {{10.1080/00150190902993267}}, volume = {{389}}, year = {{2009}}, } @article{40083, author = {{Glossmann, Jochen and Hoischen, Andreas and Roder, Thorsten and Kitzerow, Heinz-Siegfried}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, keywords = {{Condensed Matter Physics, Electronic, Optical and Magnetic Materials}}, number = {{1}}, pages = {{95--106}}, publisher = {{Informa UK Limited}}, title = {{{Asymmetric switching and storage effects in ferroelectric and antiferroelectric gels and polymers}}}, doi = {{10.1080/00150190008008011}}, volume = {{243}}, year = {{2000}}, } @article{40081, author = {{Kitzerow, Heinz-Siegfried and Slaney, Andrew J. and Goodby, John W.}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, keywords = {{Condensed Matter Physics, Electronic, Optical and Magnetic Materials}}, number = {{1}}, pages = {{61--80}}, publisher = {{Informa UK Limited}}, title = {{{Electric field-induced transition from the twist grain boundary TGBAphase to the tilted smectic SmC* phase}}}, doi = {{10.1080/00150199608007874}}, volume = {{179}}, year = {{1996}}, } @article{40079, author = {{Kitzerow, Heinz-Siegfried and Crooker, Peter P.}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, keywords = {{Condensed Matter Physics, Electronic, Optical and Magnetic Materials}}, number = {{1}}, pages = {{183--196}}, publisher = {{Informa UK Limited}}, title = {{{Polymer-dispersed cholesteric liquid crystals - challenge for research and application}}}, doi = {{10.1080/00150199108226040}}, volume = {{122}}, year = {{1991}}, }