The Magnetocaloric Effect in {[Cu(bapa)]₃[Cr(CN)₆]₂}_n · 6n H₂O at Low Temperatures

Abstract

The crystals of trCupbapaqs3rCrpCNq6s2un ¤ 6nH2O (bapa = bis(3-aminopropyl)amine) are formed by infinite Cu(II)-Cr(III) antiparallel chains, which are connected into the third direction by additive [Cu(bapa)] moieties. The onset of long-range magnetic order at 3.2 K was observed by AC susceptibility. The study of the magnetocaloric effect from magnetization measurements yields a large entropy change ¡∆SM 13.65 J K ¡1 mol ¡1 (¡∆SM 12.25 J kg ¡1 K ¡1 ) at the field change from 0 T to 3 T at temperature 4 K. The analysis of the critical behavior of ¡∆SM suggests the value of critical exponent n 0.577 at the ordering temperature characteristic for threedimensional magnets with Ising anisotropy.