Calorimetric Studies of Octacyanometalate-based Coordination Polymers Displaying Long-range Magnetic Order

Octacyanometalate-based coordination polymers are known to display an array of interesting physical and chemical properties. The presence of d electronic metals in these compounds leads to both orbital and spin contributions to uncompensated magnetic moments responsible for a rich variety of their magnetic properties. The different connectivity of metal ions leads to systems with different network dimensionality. The subclass of three-dimensional coordination polymers displays a long-range magnetic order at sufficiently low temperatures, which is revealed by the presence of a heat capacity anomaly. In the temperature and field dependence of the anomalous contributions to the heat capacity in these systems valuable information concerning the character of the ordered phase is encoded. The present review focuses on thermal properties of several particular examples of molecular magnets based on octacyanometalates and showing a longrange magnetic order. Methods of extraction of magnetic contribution to the total heat capacity are presented and discussed. Behavior of heat capacity and entropy close to the critical temperature as well as magnetocaloric effect are analyzed.