The magnetocaloric effect in {[Cu(bapa)]3[Cr(Cn)6]2}n · 6nH2O at low temperatures

Abstract

The crystals of {[Cu(bapa)]3[Cr(CN)6]2}n · 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 - δSm = 13.65 JK-1mol-1 (-δSm = 12.25 Jkg-1K-1) at the field change from 0 T to 3 T at temperature 4 K. The analysis of the critical behavior of - δSm suggests the value of critical exponent n = 0.577 at the ordering temperature characteristic for three-dimensional magnets with Ising anisotropy.