A large magnetocaloric effect of GdCoO3−δ epitaxial thin films prepared by a polymer assisted spin-coating method

Abstract

We have investigated the magnetic properties and the magnetocaloric effect of a GdCoO_3−δ epitaxial thin film which was successfully grown on a (001) LaAlO₃ substrate by a simple polymer assisted deposition (PAD) method. A paramagnetic–antiferromagnetic magnetic phase transition has been observed in the film at T_N (Gd) = 3.2 K. This film exhibits a considerable magnetocaloric effect derived from the interaction between the localized 4f moment of Gd³⁺ (J = S = 7/2 and L = 0) ions with −ΔS_M = 489.75 mJ K⁻¹ cm⁻³ for a field change of 70 kOe at T = 3.5 K. The significant magnetic entropy change together with the large refrigerant capacity indicate that the GdCoO_3−δ epitaxial thin film has potential for cryogenic magnetic cooling of microdevices and microsystems.