Magnetocaloric effect in {[Fe(pyrazole)4]2[Nb(CN)8] • 4H2O}n molecular magnet

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:354

Article

Pelka, R.¹  Konieczny, P.¹  Zielinski, P. M.¹  WasiutYnski, T.¹  Miyazaki, Y.²  Inaba, A.²  Pinkowicz, D.³  Sieklucka, B.³ 

[1] Polish Acad Sci, H Niewodniczanski Inst Nucl Phys, PL-31342 Krakow, Poland

[2] Osaka Univ, Grad Sch Sci, Res Ctr Struct Thermodynam, Toyonaka, Osaka 5600043, Japan

[3] Jagiellonian Univ, Fac Chem, PL-30060 Krakow, Poland

关键词: Magnetocaloric effect;    Molecular magnet;    Critical phenomena;   

DOI  :  10.1016/j.jmmm.2013.11.047

来源: Elsevier

【 摘 要 】

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. (C) 2013 Elsevier B.V. All rights reserved

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