The crystal structure and magnetic properties of selected fcc FeNi and Fe40Ni40B20 alloys

Abstract

The crystal structure and magnetic properties of polycrystalline alloys Fe62:5Ni37:5, Fe60Ni40, Fe50Ni50 obtained by arc-melting and Fe40Ni40B20 alloy obtained by melt spinning technique were investigated by X-ray, magnetostatic and Mössbauer effect methods. The X-ray measurements show that Fe40Ni40B20 alloy has a face-centered structure (fcc) which means that boron did not cause an amorphous rendering. The lattice constants for this alloy (a = 3:53 Å) is smaller than for FeNi alloys (a > 3:57 Å) which suggests that boron atoms were built-in in the crystal lattice. The Curie temperature of this alloy is more than 150 K higher in comparison with the of FeNi alloys, but the magnetic moment connected with this alloy is more than 0.17 ¹B/atom smaller than the magnetic moments of FeNi alloys. The shape of hyperfine field distribution for Fe40Ni40B20 is similar to the shape of hyperfine field distribution for the investigated fcc Fe62:5Ni37:5 alloy, but both are different from another investigated hyperfine field distribution of FeNi alloys.