Relaxor behaviour in a thin film of partially ordered PbSc _(0.5)Ta_(0.5)O_3 (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.
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