The influence of Cr and Ni on the character of magnetic phase transition in LaFe11.52-xMxSi1.48 alloys

The critical content of the substitution element M for Fe in LaFe11.52-xMxSi1.48 (M=Ni/Cr) alloys was studied. When the content exceeds the critical content of the element M, the nature of magnetic transition of the alloy changes from first order to second. And the relationship between phase formation and magnetic properties in LaFe11.52-xMxSi1.48 (M=Ni/Cr) alloys near critical value of Ni/Cr has been discussed sufficiently. The critical content of Ni element is x=0.08 and that of Cr is x=0.25. With the increase of Cr content, the α-Fe grows up obviously in LaFe11.52-xCrxSi1.48 alloys. The impact of partial substitution of Ni for Fe is superior to that of Cr on the magnetic properties of 1:13 phase. The substitution elements and the content of those elements have different effects on the nature of magnetic transition and magnetic entropy changes of LaFe11.52-xMxSi1.48 alloys.