Metamagnetism and Magnetocaloric Effect of LiPr(PO3)(4) Crystal

Abstract

We have studied the magnetic and magnetocaloric behaviors of a single crystal of LiPr(PO3)(4) through DC magnetization (M) and heat-capacity (C-p) measurements. The analysis of M data indicates an establishment of magnetic order at low temperatures that results in the departure of magnetic-susceptibility behavior from the Curie-Weiss law. Under the application of high magnetic fields, the antiferromagnetic ground state is unstable, leading to a first-order metamagnetic transition to a ferromagnetic phase. Because the critical field of this transition increases with increasing temperature above the Neel temperature, it is thought to be related to the spin-flop process, spin populations on multiplets, and jj-coupling. In particular, after the transition, the maximum magnetic-entropy change (Delta S-max) increases according to a power law y proportional to H-n, with n = 1.54. Under an applied field H = 50 kOe, the |Delta S-max| value at 2 K is about 9.8 J/kg K. Using thermodynamic relations and C-p(T, H) data, the largest adiabatic-temperature change of LiPr(PO3)(4) calculated at 2 K is about 2.8 K for the field of H = 20 kOe, which is attainable using a permanent magnet.