PST thin films for electrocaloric coolers

Relaxor behaviour in a thin film of partially ordered PbSc _0.5Ta_0.5O₃ (PST) was confirmed via slim P-E loops and the frequency dependence of the temperature at which the dielectric constant is maximum. Indirect measurements of the electrocaloric effect suggest that removing a field of 774 kV cm^-1 yields a temperature change of -3.5 °C to -6.9 °C over a broad range of operating temperatures near room temperature (1-127 °C), with a correspondingly large refrigerant capacity of 662 J kg^-1. In addition to low electrical hysteresis, there is negligible thermal hysteresis. PST thin films are therefore promising for EC cooling near room temperature.