Influence of modified surface effects on the magnetocaloric properties of ferromagnetic thin films

We have studied the influence of surface effects on the magnetocaloric properties of ferromagnetic thin films. Using the effective field theory, we have computed the refrigerant capacity, isothermal entropy change, and the magnetic phase transition temperature as functions of the film thickness, and surface exchange coupling. We have shown that reduced and enhanced surfaces due to the presence of modified surface exchange couplings may drastically affect the magnetocaloric properties of the system. According to our results, in contrast to the conventional bulk ferromagnetic materials, depending on the film thickness and surface exchange coupling strength, maximal entropy change in thin film systems can be observed at temperatures well below the magnetic phase transition temperature. This observation can be beneficial from view point of technological applications.