Magnetocaloric effect in {[Fe(pyrazole)(4)](2)[Nb(CN)(8)] center dot 4H(2)O}(n) molecular magnet

作者：Pelka R^*; Konieczny P; Zielinski P M; WasiutYnski T; Miyazaki Y; Inaba A; Pinkowicz D; Sieklucka B

来源：Journal of Magnetism and Magnetic Materials, 2014, 354: 359-362.

DOI：10.1016/j.jmmm.2013.11.047

• Magnetocaloric effect
• Molecular magnet
• Critical phenomena

Magnetocaloric effect in {[Fe(pyrazole)(4)](2)[Nb(Cn)(8)] center dot 4H(2)O}(n) molecular magnet is reported. It crystallizes in tetragonal 14(1)/a space group. The compound exhibits a phase transition to a long range magnetically ordered state at T-c approximate to 8.3 K. The magnetic entropy change Delta S-M as well as the adiabatic temperature change Delta T-ad due to applied field change mu(0)Delta H = 0.1, 0.2, 0.5, 1, 2, 5,9 T as a function of temperature have been determined by the relaxation calorimetry measurements. The maximum value of Delta S-M for mu(0)Delta H = 5 T is 4.9 J mol(-1) K-1 (4.8 kg(-1) K-1) at 10.3 K. The corresponding maximum value of Delta T-ad is 2.0 K at 8.9 K. The temperature dependence of the exponent n characterizing the field dependence of Delta S-M has been estimated It attains the value of 0.64 at the transition temperature, which is consistent with the 3D Heisenberg universality class.

• 出版日期2014-3