Polarization reversal induced by heating-cooling cycles in MgO doped lithium niobate crystals

Abstract

Polarization reversal during heating-cooling cycles was investigated in MgO doped lithium niobate (MgO:LN) crystal using piezoresponse force microscopy. The essential dependence of the domain structure evolution scenario on the maximal temperature in the cycle has been revealed experimentally. It has been shown that the heating of the engineered domain matrix from room temperature to 85 °C leads to light size reduction of the isolated domains at the matrix edges, whereas the heating to 170 °C leads to essential reduction of the domain size. The opposite strong effect of the domain formation and growth during cooling after pulse heating have been revealed in single domain MgO:LN. The simulation of the time dependence of the pyroelectric field during heating-cooling cycle allowed to reveal the temperature hysteresis and to explain all observed effects taking into account the temperature dependence of the bulk conductivity. © 2013 AIP Publishing LLC.