Role of orbitally degenerate Mn(III) ions in magnetic bistability of Mn5-cyanide cluster: new prospects for design of single molecule magnets with high blocking temperatures

Abstract

In this paper we report a new model aimed at the explanation of the magnetic properties of the trigonal bipyramidal cyanide cluster - [MnII (tmphen)2]3[MnIII (CN)6]2} (tmphen = 4,5,7,8-tetramethyl-1,10-phenantroline). The model explicitly takes into account the strong single-ion anisotropy associated with the unquenched orbital angular momenta of two Mn(III) ions, and satisfactory explains the observed temperature dependence of dc magnetic susceptibility. At the same time the model is compatible with firmly confirmed fact that the system represents single molecule magnet and provides the theoretical background for the design of new cyanide-based single molecule magnets with higher blocking temperatures.