Abstract |
Electroacoustic Coefficients for
Strontium Titanate in the Vicinity of Structural Phase Transition
A.Korobov, Yu.A.Brazhkin, N.I.Odina
(Department of Acoustics, Faculty of Physics, M.V. Lomonosov Moscow State
University, Moscow, Russia)
e-mail:
akor@acs465a.phys.msu.ru
The
results of experimental investigation of electroacoustic coefficients for strontium titanate single
crystal in the vicinity of structural
phase transition are presented. The measurements of relative change of 30-MHz-longitudinal wave
velocity as a function of external
electric field are carried out. Electric field is applied along or perpendicularly to the wave
propagation direction. The linear
additions to square-law dependence of ultrasound velocity as a function of electric field are
observed by approaching to phase
transition temperature in both cases. The
linear addition is more significant when electric field is perpendicular to wave propagation direction.
The linear addition appearance can be
related to piezoelectric contribution which can be explained by a deviation of lattice
symmetry from cubic that is stimulated
by defects.
Section
: 2