Abstract
It was shown that the uniaxial compressive stress applied perpendicular to the electric field strongly changes the dielectric and electromechanical properties of relaxor ferroelectric 0.9PMN:0.1PT at temperatures around its dielectric constant maximum, Tm. This includes: (i) a shift of the temperature of the electric field induced phase transition into the ferroelectric state and a depoling temperature to higher values which brings a large hysteresis in the material response to the electric field, and (ii) the symmetry breaking in the plane perpendicular to the direction of the electric field (3-axis). Using this symmetry breaking, from the ratio of the effective piezoelectric coefficients in the field biased state, d32/d31, the size of the micropolar regions at temperatures near Tm was estimated.