Magnetostrictive and magnetocaloric effects in Mn0.89Cr0.11NiGe

Abstract

The results of magnetic measurements and x-ray analysis of the Mn0.89Cr0.11NiGe alloy are presented. It is shown that the temperatures of the first-order paramagnetic structural transition from hexagonal to orthorhombic phase and paramagnetic–ferromagnetic magnetic phase transition in the orthorhombic phase can be aligned by quenching the sample. This alignment results in the change of the magnetic phase transformation order: the initially isostructural phase transition of the second order becomes a magnetostructural transition of the first order (hexagonal paramagnet–orthorhombic ferromagnet). Moreover, the character of the low-temperature ferromagnetic–antiferromagnetic transition observed in magnetic fields below 3.5 T does not change substantially. The mechanisms of the giant anisotropic magnetostrictive (up to 10%) and magnetocaloric (up to 28 J/(kg·K) upon changing the magnetic field from 0 to 5 T) effects are discussed.