Crystallographic orientation and the magnetocaloric effect in MnP

Abstract

Here we present results for single crystals of manganese phosphide (MnP), a material exhibiting a first-order ferromagnetic to paramagnetic transition at a Curie temperature of 290 K. MnP has a saturation field of about 7.5 kOe along the c-axis. Along this easy magnetic axis, ΔS was measured to be 2.2, 3.3, and 6.0 J/kg K in applied fields of 10, 20, and 50 kOe, respectively. The density of MnP is 5.49 g/cm3. No hysteresis or irreversibility was measured over a range of temperatures from 10 to 300 K.

A Simple Computational Proxy for Screening Magnetocaloric Compounds

“…In these systems, coupling of the spins and the lattice leads to a system with switchable magnetostructural state, so that a moderate magnetic field can induce a large change in the magnetic entropy of the system. 18,20,22 Inspired by these ideas, we propose here the use of computational screening to aid in discovery of new magnetocalorics. Recently, several high-throughput projects have used density functional theory (DFT) to calculate the total energies and electronic structures of hundreds of thousands of known and hypothetical materials.…”

“…In Gd 5 (Si,Ge) 4 , a first-order coupled magnetic and structural transition leads to a greatly enhanced ∆S M . [19][20][21] After the discovery of this phenomena, several other systems with known first-order magnetostructural transitions were investigated, yielding some of the most promising magnetocaloric materials, including Fe 2 P-based and La(Fe,Si) 13 -based materials. In these systems, coupling of the spins and the lattice leads to a system with switchable magnetostructural state, so that a moderate magnetic field can induce a large change in the magnetic entropy of the system.…”

Manganese phosphide thin films and nanorods grown on gallium phosphide and on glass substrates

“…Manganese phosphide (MnP) is of fundamental interest due to its unique magnetic, magneto-optical, and magneto-caloric properties [1][2][3][4][5][6][7][8][9]. Particularly at the nanoscale, MnP structures have shown significantly different properties than bulk.…”

Preferential crystallographic alignment in polycrystalline MnP

“…Single crystal studies of MnP have shown that strong magnetocrystalline anisotropy leads to a greater MCE along the easy axis [11,12]. MnP is an attractive system for this study of magnetic anisotropy because its rich magnetic phase diagram has inspired a significant body of single crystal work.…”

“…The crystal structure of MnP is orthorhombic of space group Pnma with a ¼0.5260 nm, b¼0.3174 nm, and c¼ 0.5919 nm in the paramagnetic phase at 293 K, and a ¼0.5241 nm, b¼0.3181 nm, and c¼0.5903 nm in the ferromagnetic phase at 60 K [13]. MnP undergoes a ferromagnetic to paramagnetic phase transition at a Curie temperature of 290 K [11]. In this paper we follow the c4a 4b convention for the lattice parameters.…”