Vacancy-driven magnetocaloric effect in Prussian blue analogues

TL;DR

This study demonstrates that the magnetocaloric effect in Prussian blue analogues can be tuned by controlling vacancies during synthesis, leading to significant shifts in transition temperatures and entropy changes.

Contribution

It introduces a method to tune the magnetocaloric properties of Prussian blue analogues through vacancy control during synthesis, enabling customizable magnetic cooling materials.

Findings

Magnetocaloric properties are adjustable via vacancy control.

Transition temperature shifts from 68 K to 95 K.

Large magnetic entropy changes observed.

Abstract

We experimentally show that the magnetocaloric properties of molecule-based Prussian blue analogues can be adjusted by controlling during the synthesis the amount of intrinsic vacancies. For Cs_xNi^II_4[Cr^III(CN)_6]_(8+x)/3}, we find indeed that the ferromagnetic phase transition induces significantly large magnetic entropy changes, whose maxima shift from 68 K to 95 K by varying the number of [Cr^III(CN)_6]^3- vacancies, offering an unique tunability of the magnetocaloric effect in this complex.