Magnetic properties of Sm2(Fe1−xGax)17 (x=0−0.5) compounds and their nitrides

Magnetic properties of Sm2(Fe1−xGax)17 compounds and their nitrides have been studied. Substitution of Ga for Fe leads to an increase in lattice constants. Introduction of nitrogen results in a further increase in lattice constants. Substitution of Ga for Fe causes a dramatic change of the Curie temperature of the Sm2(Fe1−xGax)17 compounds. When x=0.2 the Curie temperature is enhanced by about 200 K. X-ray-diffraction patterns of aligned samples of Sm2(Fe1−xGax)17 compounds show that alloys with x=0.15, 0.20, and 0.25 exhibit uniaxial anisotropy at room temperature. The introduction of nitrogen made the samples with x≤0.4 exhibit uniaxial anisotropy at room temperature. The Curie temperature of the nitrides decreases with the Ga concentration. The anisotropy fields of the nitrides derived from the high-field magnetization. The changes of the magnetic anisotropy, saturation magnetization, and the moment of the Fe atoms in the nitrides and their parent compounds with Ga concentration are discussed.