Enhanced Electrical and Electro‐Optic Properties of Trigonal 0.7Pb(Mg 1/3 Nb 2/3 )‐0.3PbTiO ₃ Crystal by Sm Dopant

In recent years, relaxor ferroelectric single crystals (1‐x)Pb(Mg 1/3 Nb 2/3 )O 3 ‐xPbTiO 3 (PMN‐xPT) have been widely investigated and attracted attention due to their excellent piezoelectric and electromechanical properties. Yet, their internal microdomain structure results in low transmittance, which limits their application in optical field. In this paper, 1% mol Sm‐doped 0.7Pb(Mg 1/3 Nb 2/3 )‐0.3PbTiO 3 (Sm‐PMN‐30PT) crystals were successfully grown by a modified Bridgman technique. Sm 3 + induces nanoscale structural disorder in the crystal, significantly enhancing contribution of polar nanoregions (PNRs) to macroscopic properties. Piezoelectric, ferroelectric, and electro‐optic performances were enhanced. Electromechanical coupling coefficients k 33 and k t reach 66% and 48%, respectively. Piezoelectric coefficient d 33 value of Sm‐PMN‐30PT crystal is 5800–6100 pC/N with 55 Hz test frequency. After poled along [110] direction, transmittance along [001] direction reaches 56%. Effective electro‐optic coefficient γ c is 240 pm/V at room temperature, and it can reach 1293 pm/V near the Curie temperature (109°C). These results show that Sm‐PMN‐30PT single crystals could be ideal materials for piezoelectric and electro‐optic devices.