Showing papers by "Sergey Vakhrushev published in 1999"
TL;DR: In this paper, inelastic neutron scattering experiments between 300 K and 900 K on the relaxor ferroelectric PbMg1/3Nb2/3O3 are presented.
Abstract: Results of inelastic neutron scattering experiments between 300 K and 900 K on the relaxor ferroelectric PbMg1/3Nb2/3O3 are presented. Within a mode-coupling analysis the data are consistent with the observation of a strongly damped quasi-optic excitation. It is demonstrated that below T
d ≈ 650 K a dynamical crossover takes place manifesting itself by a narrow central peak. This crossover is accompanied by the appearance of strong damping of the transverse acoustic phonons, with the damping constant proportional to q
4. Different physical models of the crossover are discussed.
110 citations
TL;DR: In this article, large quantities of highly dispersed ferroelectric objects were obtained by impregnation of two porous dielectric matrixes (porous glass and artificial opal) with molten Ferroelectric materials (NaNO2, KH2PO4 (KDP)).
31 citations
TL;DR: The results of X-ray high-temperature study of (PbMg1/3Nb2/3O3)1-x-(PbTiO3),x (x=0.06, 0.1, and 0.4) are presented in this paper.
Abstract: The results of X-ray high-temperature study of (PbMg1/3Nb2/3O3)1-x-(PbTiO3)x (x=0.06; 0.1; 0.4) are presented. The structure refinement is performed and the results of the refinement are used to calculate the probability density function ρ(σ). It is demonstrated that at x=0.06 and x=0.1 the center of gravity of ρ(σ) for the lead ions is shifted from the ideal (000) position, while at x=0.4 the bell-shaped distribution has the maximum at σ=0. The disappearance of the shifts of lead ions at x=0.4 is considered as an evidence of the suppression of the local electric and elastic fields essential for the relaxor phenomena
5 citations
TL;DR: In this paper, the static or dynamic disordered shifts and anharmonic thermal motions of the different atoms are compared and discussed in connection with the dielectric properties and the existence of structural phase transitions.
Abstract: New X-ray and neutron diffraction results for simple perovskites PbTiO3, BaTiO3 and complexes PbxBa1-xSc1/2Nb1/2O3 are presented. The static or dynamic disordered shifts and anharmonic thermal motions of the different atoms are compared and discussed in connection with the dielectric properties and the existence of structural phase transitions.
3 citations
TL;DR: An x-ray diffraction study of the paraphase of the (PbMg1/3Nb2/3O3)0.4 solid solution has been found to exhibit a clearly pronounced ferroelectric transition.
Abstract: An x-ray diffraction study of the paraphase of the (PbMg1/3Nb2/3O3)0.6-(PbTiO3)0.4 solid solution has been found to exhibit a clearly pronounced ferroelectric transition. It is shown that Pb2+ ions occupy a special position (000), as opposed to pure PMN and other relaxor ferroelectrics, where they are displaced from it in random directions. The absence of these displacements indicates suppression of frozen-in random electric fields in this compound.
2 citations