Magnetorefrigeration capability of a gadolinium(III) coordination polymer containing trimesic acid: a correlation between the isothermal magnetic entropy change and the gadolinium content

The Gd(III) coordination polymer [Gd(mes)(H2O)(6)](n) (1), where H3mes stands for trimesic acid, was subjected to variable temperature/ field magnetizations and heat capacity measurements. Analyses of the magnetic data revealed negligible magnetic interactions (zJ = -0.39 cm(-1)) and the isothermal magnetic entropy change -Delta S-M = 36.0 J K-1 kg(-1) at T = 2 K and B = 9 T. The evaluation of the heat capacity data resulted in a similar value of -Delta S-M = 34.8 J K-1 kg(-1). Thus, compound 1 shows a quite large magnetocaloric effect among Gd(III)-based molecular coolants. Furthermore, the correlation of the magnetocaloric effect based on the mass concentration of Gd atoms (c(m)(Gd)) was proposed as -Delta S-M =39.5c(m)(Gd)(0.364) taking into account the experimental data for more than thirty Gd(III) compounds.