Low-pressure-induced giant barocaloric effect in an all-d-metal Heusler Ni35.5Co14.5Mn35Ti15 magnetic shape memory alloy

Zhiyang Wei,Bing Li,Jianping Guo,Yi Shen,Jian Liu,Zhe Zhang,Enke Liu,Zhidong Zhang

doi:10.1063/5.0005021

Abstract

The clean and energy-efficient solid-state refrigeration based on magnetostructural phase transformation is a promising alternative technology for vapor-compression refrigeration. Herein, using a unique quasi-direct calorimetric method in a high hydrostatic pressure condition, we have studied the barocaloric effect for a Ni35.5Co14.5Mn35Ti15 all-d-metal Heusler alloy that undergoes a martensitic transformation accompanied by a large magnetization change. The martensitic transformation is found to be sensitive to either applied pressure or magnetic field with the large transformation temperature driving rates of 5.8 K kbar−1 and 2.0 K T−1. Such a sensitive response to external stimuli originates from the large lattice/volume- and magnetization-discontinuity on the phase transformation. The Ni35.5Co14.5Mn35Ti15 alloy exhibits a large barocaloric effect with an isothermal entropy change of −24.2 J kg−1 K−1and an adiabatic temperature change of 4.2 K, concomitant with a relatively low pressure change of 1 kbar, appearing to be the largest values among those of reported magnetic shape memory alloys. Moreover, by virtue of the strong magnetostructural coupling in the Ni35.5Co14.5Mn35Ti15 alloy, we propose a strategy of applying/releasing pressure and magnetic field in a proper sequence to eliminate the hysteresis and effectively enhance the reproducibility of the barocaloric effect.

Highlights

Ferromagnetic and non-magnetic shape memory alloys (SMAs) undergoing a martensitic transformation (MT) have been extensively studied in terms of their MCE7,12–16 and eCE8,17–19 for the past few years.20 Exploring on the BCE of SMAs is at the early stage and has been arousing research interest for its potential on refrigeration very recently.11,21–25 The previous findings on hydrostatic pressure-induced colossal entropy change in organic or organic–inorganic frameworks compounds featured by a giant compressibility emphasize the importance of the BCE on solid state refrigeration
Using a unique quasi-direct calorimetric method in a high hydrostatic pressure condition, we have studied the barocaloric effect for a Ni35.5Co14.5Mn35Ti15 all-d-metal Heusler alloy that undergoes a martensitic transformation accompanied by a large magnetization change
The recently developed all-d-metal Heusler alloys based on the concept of d–d hybridization have been reported to exhibit outstanding properties superior to conventional Heusler alloys, such as larger latent heat, more considerable volume/lattice discontinuity associated with the MT, and better mechanical properties

Summary

Introduction

Ferromagnetic and non-magnetic shape memory alloys (SMAs) undergoing a martensitic transformation (MT) have been extensively studied in terms of their MCE7,12–16 and eCE8,17–19 for the past few years.20 Exploring on the BCE of SMAs is at the early stage and has been arousing research interest for its potential on refrigeration very recently.11,21–25 The previous findings on hydrostatic pressure-induced colossal entropy change in organic or organic–inorganic frameworks compounds featured by a giant compressibility emphasize the importance of the BCE on solid state refrigeration. Using a unique quasi-direct calorimetric method in a high hydrostatic pressure condition, we have studied the barocaloric effect for a Ni35.5Co14.5Mn35Ti15 all-d-metal Heusler alloy that undergoes a martensitic transformation accompanied by a large magnetization change.

Results

Conclusion