In this article, our recent progresses about the effects of atomicsubstitution, magnetic field and temperature on the magnetic and magnetocaloricproperties of the LaFe13-xAlx compounds are reviewed. With the increase ofaluminum content, the compounds exhibit successively an antiferromagnetic(AFM), a ferromagnetic (FM), and a mictomagnetic state. Furthermore, the AFMcoupling of LaFe13-xAlx can be converted to a FM coupling by substituting Sifor Al, Co for Fe and magnetic rare-earth R for La, or introducing interstitialC or H atom. However, low doping levels lead to FM clusters embedded in AFMmatrix, and the resultant compounds can undergo, under appropriate appliedfields, first an AFM-FM and then a FM-AFM phase transition while heated, withsignificant magnetic relaxation in the vicinity of the transition temperature.The Curie temperature of LaFe13-xAlx can be shifted to room temperature bychoosing appropriate contents of Co, C or H, and strong magnetocaloric effectcan be obtained around the transition temperature. For example, for theLaFe11.5Al1.5C0.2H1.0 compound, the maximal entropy change reaches 13.8 J/kg Kfor a field change of 0-5 T, occurring around the room temperature. It is 42%higher than that of Gd and, therefore, this compound is a promisingroom-temperature magnetic refrigerant.
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