Enhanced electric property of relaxor ferroelectric crystals with low AC voltage high-temperature poling

Abstract

Abstract We demonstrated high free dielectric permittivity ( ε 33 T / ε 0 ) > 8000 and piezoelectric coefficient d 33 > 1950 pC/N of 72Pb(Mg 1/3 Nb 2/3 )O 3 -28PbTiO 3 (PMN–28PT) single crystals (SCs) obtained by low-voltage AC poling (LV ACP) of 1.5 to 3.5 kV RMS cm −1 at a high temperature (HT) of 80 °C in an air atmosphere. The minimum standard deviation ( σ ) of 170 was similar to conventional DC poling (DCP) and a high average ε 33 T / ε 0 of 8800 was confirmed with a 2.0 k V RMS cm −1 of ACP for five samples. The ACP voltages were less than 50% compared with previous studies of 2.9 to 8.5 k V RMS cm −1 . We assume ACP at 80 °C with a frequency of 0.1 Hz decreased coercive field E C the most which led to easy poling reversal. The LVHT air ACP process is very effective in obtaining enhanced dielectric and piezoelectric properties for PMN–PT SC transducers for medical echo ultrasound equipment application with less risk of breakdown and organic solvent-free for poling.