The Magnetocaloric Effect in the Thin Film of a Prussian Blue Analogue

Abstract

Investigation of the magnetocaloric effect (MCE) in the thin film of nickel hexacyanochromate obtained by “layer‐by‐layer” deposition is reported. This compound shows a sharp phase transition to a long‐range ferromagnetically ordered state at Tc = 66 K. In order to check the shape anisotropy effect, the properties of the thin film were investigated for the sample aligned parallel and perpendicular to the direction of an applied magnetic field. The demagnetizing field was smaller than the fields used to observe the MCE. For the fields higher than 1 T, values of the magnetic entropy change obtained for both film orientations are similar reaching 7.43 J kg–1 K–1 and 7.07 J kg–1 K–1 at µ0H = 5 T for parallel and perpendicular orientations, respectively. The n exponent characterizing the field dependence of the entropy change is the same and equals 0.72 ± 0.02 at Tc. Scaling analysis to obtain the master curves of the entropy temperature dependence was performed for both film orientations.