Investigating the temperature-dependent electro-optic behaviors in La-doped PMN-PT transparent ceramics

Understanding the temperature-dependent electro-optic behaviors in (1 − x)[Pb(Mg1/3Nb2/3)O3]-x[PbTiO3] [(1 − x)PMN-xPT] is central to its device applications. In this work, 0.5 mol. % La-(1 − x)PMN-xPT transparent ceramics with different solid solution ratios (i.e., x = 0.10, 0.15, 0.20, 0.25) were fabricated to study the temperature-dependent electro-optic behaviors. Two distinct temperature dependencies are revealed: for 0.85PMN-0.15PT and 0.90PMN-0.10PT, the measured electro-optic coefficient decreases with increasing temperature, while for 0.75PMN-0.25PT and 0.80PMN-0.20PT, the electro-optic coefficient first increases and then decreases rapidly with the increase in temperature. Based on the temperature-dependent dielectric, ferroelectricity, x-ray diffraction, and piezoresponse domain image analysis, the ferroelectric–ferroelectric phase transition is suggested to play a dominant role, with the ferroelectric state to relaxor state transition providing an auxiliary enhancement. This study provides valuable insights into understanding temperature-dependent electro-optic behaviors and should be instructive for the design and optimization of advanced electro-optic devices.