Magnetocaloric effect in hexacyanochromate Prussian blue analogs

We report on the magnetocaloric properties of two molecule-based hexacyanochromate Prussian blue analogs, nominally CsNiII[Cr-III(CN)(6)]center dot(H2O) and Cr-3(II)[Cr-III(CN)(6)](2)center dot 12(H2O). The former orders ferromagnetically below T-C similar or equal to 90 K, whereas the latter is a ferrimagnet below T-C similar or equal to 230 K. For both, we find significantly large magnetic entropy changes Delta S-m associated with the magnetic phase transitions. Notably, our studies represent an attempt to look at molecule-based materials in terms of the magnetocaloric effect for temperatures well above the liquid helium range.