Giant solid-state barocaloric effect in the Ni–Mn–In magnetic shape-memory alloy

Abstract

The search for materials showing large caloric effects close to room temperature has become a challenge in modern materials physics and it is expected that such a class of materials will provide a way to renew present cooling devices that are based on the vapour compression of hazardous gases. Up to now, the most promising materials are giant magnetocaloric materials. The discovery of materials showing a giant magnetocaloric effect at temperatures close to ambient has opened up the possibility of using them for refrigeration. As caloric effects refer to the isothermal entropy change achieved by application of an external field, several caloric effects can take place on tuning different external parameters such as pressure and electric field. Indeed the occurrence of large electrocaloric and elastocaloric effects has recently been reported. Here we show that the application of a moderate hydrostatic pressure to a magnetic shape-memory alloy gives rise to a caloric effect with a magnitude that is comparable to the giant magnetocaloric effect reported in this class of materials. We anticipate that similar barocaloric effects will occur in many giant-magnetocaloric materials undergoing magnetostructural transitions involving a volume change.

Multicaloric effect in ferroelectric PbTiO3from first principles

“…Contrary to the old belief that such effects, while common, are miniscule, a large variety of giant caloric effects has been recently discovered in some ferroic materials [1][2][3][4][5][6][7][8][9][10] . These discoveries have opened the door to the use of these giant effects in an efficient and environmentally friendly solid-state refrigeration technology.…”

Inverse barocaloric effect in the giant magnetocaloric La–Fe–Si–Co compound

“…7). From calorimetric curves at selected values of the hydrostatic pressure p , the entropy change (referenced to a given state at T 0 ) is computed as:…”

“…Th e tuning parameter for the caloric eff ect (external fi eld) can be any generalized thermodynamic force, provided that the change in the conjugated generalized thermodynamic displacement is large enough. Hence, giant caloric eff ects have already been reported for magnetic fi eld (magnetocaloric eff ect) 1 -3 , electric fi eld (electrocaloric eff ect) 4,5 , uniaxial stress (elastocaloric eff ect) 6 and hydrostatic pressure (barocaloric eff ect) 7,8 .…”

“…In a recent work 7 , we postulated that most giant magnetocaloric materials would also exhibit large barocaloric eff ects. Th is claim is also supported by recent theoretical studies 9,10 .…”

Stable magnetostructural coupling with tunable magnetoresponsive effects in hexagonal ferromagnets

“…These effects are of interest for many potential technological applications like magnetic actuators 13,14 , sensors 15 , energy-harvesting devices 16 and solid-state magnetic refrigeration 17 . In these functionalities, the magnetostructural coupling between the structural and the magnetic transition has an essential role.…”