In situ Raman scattering studies of pressure-temperature phase diagrams in antiferroelectric xCaSnO₃-modified NaNbO₃ ceramics Available to Purchase

As one of the classic antiferroelectrics, high complexity of a NaNbO₃ structure sequence attracts great attention in the ferroelectric physics field. Here, temperature-pressure phase diagrams as a function of a CaSnO₃ content for antiferroelectric (1-x)NaNbO₃-xCaSnO₃ ceramics have been improved by Raman spectroscopy. We clarify structural order of phase transitions on CaSnO₃-modified NaNbO₃ ceramics within the temperature range of 80–840 K by discussing the anomalies of lattice and phonon dynamics. The doping effect of CaSnO₃ on the P-R phase transition has been summarized from the decreased critical temperature from 660 to 580 K. The intermediate phase at 480 K was recognized as an incommensurate phase. In addition, the anomalous pressure with respect to phonon frequency at the stress field of 0–25 GPa also provides the evidence of structural transformations at 6.55 and 10.05 GPa. Upon increasing the CaSnO₃ content, phase transition moves to a lower pressure range. This work would provide the powerful supplement of phase transitions for the broad NaNbO₃-based crystalline family with Raman scattering.