%0 Journal Article %1 WOS:000259264900031 %A Maczka, M %A Paraguassu, W %A Filho, A G Souza %A Freire, P T C %A Majchrowski, A %A Filho, J Mendes %A Hanuza, J %C ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA %D 2008 %I AMER PHYSICAL SOC %J PHYSICAL REVIEW B %K imported %N 6 %R 10.1103/PhysRevB.78.064116 %T Lattice dynamics and high-pressure Raman scattering studies of ferroelectric K(2)MgWO(2)(PO(4))(2) %V 78 %X K(2)MgWO(2)(PO(4))(2) ferroelectric single crystal, derived from KTiOPO(4) (KTP) by replacement of two Ti(4+) ions with Mg(2+) and W(6+) cations, was investigated at ambient pressure by micro-Raman scattering and infrared spectroscopies with a focus on polarization properties of vibrational modes. These results were analyzed based on classical lattice dynamics calculations which allowed to propose the normal-mode symmetries and assignments. In addition to the ambient pressure studies, high-pressure Raman scattering studies were performed. These studies showed the onset of a reversible first-order phase transition near 2.0 GPa which is associated with marked softening of the low wave number mode corresponding to motions of the K(+) ions. The structural changes at the phase transition are relatively weak and either the crystal exhibits transformation from the ambient pressure P1 to a high-pressure monoclinic structure or there is no symmetry change at the phase transition, i.e., this transition is isosymmetric.

@article{WOS:000259264900031, abstract = {K(2)MgWO(2)(PO(4))(2) ferroelectric single crystal, derived from KTiOPO(4) (KTP) by replacement of two Ti(4+) ions with Mg(2+) and W(6+) cations, was investigated at ambient pressure by micro-Raman scattering and infrared spectroscopies with a focus on polarization properties of vibrational modes. These results were analyzed based on classical lattice dynamics calculations which allowed to propose the normal-mode symmetries and assignments. In addition to the ambient pressure studies, high-pressure Raman scattering studies were performed. These studies showed the onset of a reversible first-order phase transition near 2.0 GPa which is associated with marked softening of the low wave number mode corresponding to motions of the K(+) ions. The structural changes at the phase transition are relatively weak and either the crystal exhibits transformation from the ambient pressure P1 to a high-pressure monoclinic structure or there is no symmetry change at the phase transition, i.e., this transition is isosymmetric.}, added-at = {2022-05-23T20:00:14.000+0200}, address = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA}, author = {Maczka, M and Paraguassu, W and Filho, A G Souza and Freire, P T C and Majchrowski, A and Filho, J Mendes and Hanuza, J}, biburl = {https://www.bibsonomy.org/bibtex/2b396936f65f1c16f763ea3dec6daee56/ppgfis_ufc_br}, doi = {10.1103/PhysRevB.78.064116}, interhash = {c973b0c139f18a077469283f237ef79e}, intrahash = {b396936f65f1c16f763ea3dec6daee56}, issn = {1098-0121}, journal = {PHYSICAL REVIEW B}, keywords = {imported}, number = 6, publisher = {AMER PHYSICAL SOC}, pubstate = {published}, timestamp = {2022-05-23T20:00:14.000+0200}, title = {Lattice dynamics and high-pressure Raman scattering studies of ferroelectric K(2)MgWO(2)(PO(4))(2)}, tppubtype = {article}, volume = 78, year = 2008 }