3d-4f spin interaction induced giant magnetocaloric effect in zircon-type DyCrO4 and HoCrO4 compounds

• Published in: Applied physics letters 2013-08, Vol.103 (9)
• Main Authors: Midya, A., Khan, N., Bhoi, D., Mandal, P.
• Format: Article
• Language: English
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4819768

We have investigated the influence of 3d-4f spin interaction on magnetic and magnetocaloric properties of DyCrO4 and HoCrO4 compounds by magnetization and heat capacity measurements. Both the compounds exhibit complicated magnetic properties and huge magnetic entropy change around the ferromagnetic transition due to the strong competition between ferromagnetic and antiferromagnetic superexchange interactions. For a field change of 8 T, the maximum values of magnetic entropy change (ΔSMmax), adiabatic temperature change (ΔTad), and refrigerant capacity (RC) reach 29 J kg−1 K−1, 8 K, and 583 J kg−1, respectively, for DyCrO4 whereas the corresponding values for HoCrO4 are 31 J kg−1 K−1, 12 K, and 622 J kg−1. ΔSMmax, ΔTad, and RC are also quite large for a moderate field change. The large values of magnetocaloric parameters suggest that the zircon-type DyCrO4 and HoCrO4 could be the potential magnetic refrigerant materials for liquefaction of hydrogen.