Spin re-orientations in Nd(Fe,Co)10V2 system

Abstract The effect of cobalt substitution for iron on the spin re-orientation temperature in tetragonal NdFe 10− x Co x V 2 alloys ( x =0 3 and 5) has been investigated using X-ray, magneto-thermogravimetric and ac susceptibility techniques. At room temperature for x =0, NdFe 10 V 2 exhibits a uniaxial anisotropy, which is found to be strongly modified by cobalt substitution in Nd(Fe,Co) 10 V 2 alloys. In fact, alloys with x =3 and 5 were found to possess planar anisotropy at this temperature. The NdFe 10 V 2 and NdFe 5 Co 5 V 2 compounds were observed to exhibit spin re-orientations at 124 and ≈ 350 K, respectively. These appear to be cone to axial ( x =0) and plane to cone ( x =5) re-orientations with increasing temperature. The NdFe 7 Co 3 V 2 alloy undergoes two spin transitions: one at 210 K and the second at 518 K. The spin structure thus appears to be from a cone to planar, and planar to axial-type, respectively, with increasing temperatures. Thus, the substitution of cobalt in NdFe 10 V 2 causes the spin re-orientation to shift to higher temperatures.