Large barocaloric effect with high pressure-driving efficiency in hexagonal MnNi0.77Fe0.23Ge alloy

Abstract

The hydrostatic pressure is expected to be an effective knob to tune the magnetostructural phase transitions of hexagonal MMX alloy. In this study, magnetization measurements under hydrostatic pressure were performed on a MMX martensitic MnNi0.77Fe0.23Ge alloy. The magnetostructural transition temperature can be efficiently tuned to lower temperatures by applying moderate pressures, with a giant shift rate of -151 K GPa-1. A temperature span of 30 K is obtained under the pressure, within which a large magnetic entropy change of -23 J kg-1 K-1 in a field change of 5 T is induced by the mechanical energy gain due to the large volume change. Meanwhile, a decoupling of structural and magnetic transitions is observed at low temperatures when the martensitic transition temperature is lower than the Curie temperature. These results show a multi-parameter tunable caloric effect that benefits the solid-state cooling.

8 pages, 4 figs

References in corpus (9)

• Stable magnetostructural coupling with tunable magnetoresponsive effects in hexagonal phase-transition ferromagnets
• Colossal barocaloric effects near room temperature in plastic crystals of neopentylglycol
• Giant and reversible extrinsic magnetocaloric effects in La0.7Ca0.3MnO3 films due to strain
• Vacancy-tuned paramagnetic/ferromagnetic martensitic transformation in Mn-poor Mn_{1-x}CoGe alloys
• Effects of hydrostatic pressure on the magnetism and martensitic transition of Ni-Mn-In magnetic superelastic alloys
• Unprecedentedly Wide Curie-Temperature Windows as Phase-Transition Design Platform for Tunable Magneto-Multifunctional Materials
• Pressure induced magnetic and magnetocaloric properties in NiCoMnSb Heusler alloy
• Magnetostructural Transformation and Magnetoresponsive Properties of MnNiGe1-xSnx Alloys
• Windows open for highly tunable magnetostructural phase transitions