Citation:
T. M. Correia, J. S. Young, R. W. Whatmore, J. F. Scott, N. D. Mathur and Q. Zhang, Investigation of electrocaloric effect in PMN-PT relaxor thin films, Applied Physics Letters, Volume 95, Issue 18, 2009. Paper Number 182904.
Abstract:
Permittivity measurements of a 0.93PMN-0.07PT thin film show a broad maximum near 35 ºC, and an anomaly at the depolarizing temperature Td = 18 ºC on heating only, suggesting a dipolar glass-relaxor phase transition. No structural phase transition at 18 ºC is apparent from ferroelectric hysteresis loops taken on field cooling and field heating. These loops show the thermal hysteresis expected for ferroelectric relaxors, which has not hitherto been experimentally verified in PMN-PT thin films. Our data suggest the intriguing possibility of a giant electrocaloric effect (DT = 9 K, DE = 720 kV cm-1) at and near room temperature.
