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arXiv · 0808.2835

Giant Magnetocaloric Effect in Re-entrant Ferromagnet PrMn1.4Fe0.6Ge2

R. Zeng·J. L Wang·L. Lu·W. X. Li·S. J. Campbell·S. X. Dou
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Abstract

Three first order magnetic phase transitions (FOMT) have been detected at TCPr, TNinter and TCinter over the temperature range from 5 K to 340 K at fields up to 9 T in PrMn1.4Fe0.6Ge2, and the magnetocaloric effect (MCE) around these transitions evaluated. The MCE of two FOMT from planar antiferromagnetism (AFl) to c-axis ferromagnetism (Fmc) around 168 K, and from the Fmc state to the c-axis AFmc state around 157 K have acceptable values compared with those of existing MCE systems. A giant magnetocaloric effect (GMCE) has been observed around 25.5 K associated with the field-induced FOMT from the AFmc to the Fmc+F(Pr) state with an additional Pr magnetic contribution. The MCE value 29.1 J/kg K with field change 7 T is comparable to and even larger than reported values for the best-performed MCE materials. In particular, the giant MCE value of 12.3 J/kg K obtained for the relatively small field change from 0 to 1 T is very beneficial for applications, and this, together with the small magnetic and thermal hysteresis, suggests that PrMn1.4Fe0.6Ge2 may be a promising candidate for magnetic refrigeration applications in the hydrogen liquefication temperature range.

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R. Zeng, J. L Wang, L. Lu, W. X. Li, S. J. Campbell, S. X. Dou. 2008-09-01. Giant Magnetocaloric Effect in Re-entrant Ferromagnet PrMn1.4Fe0.6Ge2. https://arxiv.org/abs/0808.2835

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