Giant low-field magnetocaloric effect and refrigerant capacity in reduced dimensionality EuTiO3 multiferroics

Engineering magnetic materials into a thin film form while preserving its excellent magnetocaloric response is essential in the development of miniature magnetic coolers. We demonstrate how this can be achieved in the case of EuTiO3 - an emerging multiferroic material. Unlike conventional cases where reduced dimensionality considerably decreased the magnetic entropy change (Delta S-M) and hence the refrigerant capacity (RC), we show the large low-field enhancements of Delta S-M and RC in a similar to 100 nm thick nanocrystalline EuTiO3 film (Delta S-M similar to 24 J kg(-1)K(-1) and RC = 152 J kg(-1) for mu(0)Delta H = 2 T) relative to its single crystal counterpart (Delta(SM) similar to 17 J kg(-1)K(-1) and RC similar to 107 J kg(-1) for mu(0)Delta H = 2 T). The nanocrystalline EuTiO3 film is an excellent candidate for cryogenic magnetic refrigeration. From our study, a new approach for improving both MCE and RC in magnetic nanomaterials is proposed, which will stimulate further research on magnetocaloric thin films and related cooling devices. (C) 2020 Elsevier B.V. All rights reserved.