A Mössbauer effect study of the magnetic properties of Nd2(Fe1−xCox)14B and Y2(Fe1−xCox)14B

Abstract

The atomic and magnetic structures of Nd2(Fe1−xCox)14B, with x equal to 0.0, 0.1, 0.2, and 0.3, and Y2(Fe1−xCox)14B, with x equal to 0.0, 0.1, 0.2, 0.3, and 0.4, have been investigated by Mössbauer spectroscopy at room temperature and 85 K. A Mössbauer effect spectral component analysis, based on neutron diffraction site populations in Nd2(Fe1−xCox)14B, has revealed a stronger compositional dependence for the hyperfine field and magnetic moment on the j2 site than is observed for the other five iron sites. A similar analysis for the Y2(Fe1−xCox)14B compounds shows lower hyperfine fields and hence moments on the c and e sites, as well as a significant decrease in the hyperfine field at the j1 site as the cobalt concentration is increased. The iron site hyperfine fields, and their dependence on cobalt content, are consistent with the local site coordination environments in both series of compounds.