Phase transitions and magnetocaloric effect in MnAs, MnAs0.99P0.01, and MnAs0.98P0.02 single crystals

• DOI: 10.1134/s002016851301007x
• Publication Date: 2012-12-14T23:19:32Z
• Authors: V. I. Mitsiuk; G. A. Govor; M. Budzyński
• Keywords: Magnetic refrigeration; Basal plane; Lattice (music)

We have examined the influence of external magnetic fields up to H = 14 T on the phase transitions of MnAs, MnAs0.99P0.01, and MnAs0.98P0.02 single crystals. The results indicate that there is structural instability of the crystal lattice, associated with anomalous compression at temperatures from \(T_{f_1 }\) ≃ 250 K to the phase transition temperature Tu and anomalous lattice expansion in the basal plane between Tu and \(T_{f_2 }\) ≃ 350 K. Near the first-order phase transition, the magnetic entropy change at a magnetic field change from 0 to 14 T is about 40 J/(kg K) in single-crystal MnAs and approaches 50 J/(kg K) in single-crystal MnAs0.98P0.02.