Giant Magnetocaloric Effect in Manganites

Abstract

In this review we briefly discuss the magnetocaloric properties of the manganites. It is evidenced that the maximum entropy change observed in manganites exceeds that of gadolinium (the prototype material for room temperature refrigerators). For the manganites characterized by second-order magnetic phase transitions the scaling hypothesis is discussed. It is shown that simple phenomenological model with only one fitting parameter, presented in this paper, satisfactorily describes experimental observations.

Magnetocaloric effect in Fe–Cr–Cu–Nb–Si–B amorphous materials

“…The ferromagnetic-to-paramagnetic transition in these alloys is not as sharp as in perovskite type materials, which are considered as suitable for application in magnetic refrigerators [9][10]. However, in the alloy containing 8 at.% Cr this transition occurs close to the room temperature, which is illustrated in Fig.…”

Viable Materials with a Giant Magnetocaloric Effect

“…; Tm in TmZn [198] and metallic glasses [233]; rare earth in clathrates [277,296], etc. Manganites [258] include La 0.7 Ca 0.3 MnO 3 [227,262,264,285], La 0.48 Ca 0.52 MnO 3 [174], Na-deficient La 0.8 Na 0.2−x MnO 3 [185], La 0.67 Sr 0.16 Ca 0.17 MnO 3 [207], La 0.8−x K x Ba 0.05 Sr 0.15 MnO 3 [297], as well as containing critical rare earth La 0.7−x Pr x Ca 0.3 MnO 3 [160], GdMnO 3 [186], Gd 2 NiMnO 6 and Gd 2 CoMnO 6 [193], TbMnO 3 [165,252], DyMnO 3 [247], PrPb manganites [294], etc. Materials containing highly toxic arsenic include MnAs [123,131,210,238,245,246,256,265,273,276,282,289] and MnFe(P,As) [48,49,239,298].…”

Influence of higher sodium substitutions on magnetic entropy change and transition temperature in lanthanum manganites

“…11 Many other materials such as Laves phases (La(FeSi)), MnAs, heusler alloys and rare-earth manganites are also being increasingly investigated for magnetic refrigeration. 12,13 Manganites have an advantage of tunable magnetic properties with respect to substituting elements and the potential of developing a near room temperature magnetic refrigerant. 14 A survey of literature also reveals that though compositions having lower substitutions of sodium (Na) in LaMnO 3 (LMO) have been investigated and thoroughly studied, there exists no report on higher sodium substitution above 50%.…”