Polarization-strain coupling in the mixed ferroelectricKTa1−xNb

Order–disorder behavior of ferroelectric phase transition of KTa1−xNbxO3 probed by Brillouin scattering

“…The size is about 6 nm at T ‫ء‬ , which is in agreement with the size of dynamic polar clusters of 4-6 nm. 22 Therefore, a cubic-tetragonal phase transition of the KTN clearly indicates a critical slowing down of PNRs, which is in agreement with the increasing size of the PNRs. The growth of PNRs in a cubic phase also enhances the softening of c 11 as shown in Fig.…”

“…The local polarization fluctuation of PNRs in a cubic phase induces local strain fluctuations by piezoelectricity of PNRs. 22,23 And the KTN with the high Nb concentration, the PNRs orientated between ͓111͔ directions tends to fix their orientation along one of ͓100͔ directions. 23 Therefore, the softening of c 11 which correspond to longitudinal distortion indicates the interaction between the LA mode and the local polarization fluctuations of PNRs.…”

“…22,23 As to the precursor phenomenon of a cubic-tetragonal transition, the softening of c 11 from T B to T C-T on further cooling is caused by the interaction with dynamic PNRs in a cubic phase. 22,23 In order to obtain accurate data of the CP, we measured in the wide frequency range Ϯ560 GHz with a bigger FSR = 300 GHz as shown in Fig. 1͑b͒.…”

Highly sensitive simple homodyne phase detector for ultrasonic pulse-echo measurements

“…All of the measured dependences agree with those obtained previously on similar KTN crystals 20,21 . However, one can see that the broad dynamic range and high sensitivity of the AD8302 microchip allowed for recording the ultrasound signal throughout the whole sequence of ferroelectric transitions with a good signal-to-noise ratio, as shown in Figures 8 (a-c).…”

Broadband light scattering of two relaxation processes in relaxor ferroelectric0.93Pb(Zn1/3Nb2/3Tsukada1, Kojima2 2008Phys. Rev. B973810View full textAdd to dashboardCite

“…In some Pb-free perovskite structure, e.g., KTa 1−x Nb x O 3 , 180°flipping is not usual, and it is considered that non-180°fl ipping dominates the CP behavior. 30 This is because the hopping of the B-site ion in the perovskite structure is the origin of the local polarization in the case of normal perovskite ferroelectrics. On the other hand, in Pb-containing relaxor ferroelectrics, every ion shows displacement from their ideal positions of the cubic perovskite structure.…”