Fe—Si—La alloy having excellent magneto-caloric properties

摘要

The invention relates to a Fe—Si—La alloy having the atomic composition:
(La1-a-a′MmaTRa′)1[(Fe1-b-b′CObMb′)1-x(Si1-cXc)x]13(CdNeH1-d-e)y(R)z(I)f Mm representing a mixture of lanthanum, cerium, neodymium and praseodynium in the weight proportion of 22 to 26% La, 48 to 53% Ce, 17 to 20% Nd and 5 to 7% Pr, the said mixture possibly comprising up to 1% by weight of impurities,TR representing one or more elements of the rare earth family other than lanthanum,M representing one or more type d transition elements of the 3d, 4d and 5d layersX representing a metalloid element selected from Ge, Al, B, Ga and InR representing one or more elements selected from Al, Ca, Mg, K and Na,I representing one or two elements selected from O and S, with:
0≦a<0.5 and 0≦a′<0.20≦b≦0.2 and 0≦b′<0.40≦c≦0.5 and 0≦d≦10≦e≦1 and f≦0.10.09≦x≦0.13 and 0.002≦y≦40.0001≦z≦0.01the subscripts b, d, e, x and y being such that the alloy further satisfies the following condition:
6.143b(13(1−x))+4.437y[1−0.0614(d+e)]≧1  Eq.1d*y≧0.005  Eq.2;It also relates to a powder of this alloy or to a mixture of these alloys and the method of fabrication.

主权项

1. An Fe—Si—La alloy comprising:
(La1-a-a′MmaTRa′)1[(Fe1-b-b′CObMb′)1-x(Si1-cXc)x]13(CdNeH1-d-e)y(R)z(I)f, wherein Mm represents a mixture of lanthanum, cerium, neodymium and praseodynium in the weight proportion of 22 to 26% La, 48 to 53% Ce, 17 to 20% Nd, and 5 to 7% Pr, said mixture comprising up to 1% by weight of impurities; TR represents at least one rare earth family element other than lanthanum; M represents at least one type d transition element of the 3d, 4d, or 5d layers; X represents a metalloid element selected from the group consisting of Ge, Al, B, Ga, and In; R represents at least one element selected from the group consisting of Ca, Mg, K, and Na; and I represents one or two elements selected from the group consisting of O and S;
0≦a<0.5 and 0≦a′<0.2;0≦b≦0.2 and 0≦b′<0.4;0≦c≦0.5 and 0≦d≦1;0≦e≦1 and f≦0.1;0.09≦x≦0.13 and 0.002≦y≦4;0.0001≦z≦0.01; and subscripts b, d, e, x and y are such that:
6.143b(13(1−x))+4.437y[1−0.0614(d+e)]≧1, andd×y≧0.005.