Origin of magnetism in amorphous Ni<SUB>81.6</SUB>B<SUB>18.4</SUB> alloy

Ferromagnetic resonance (FMR) measurements have been performed on amorphous Ni81.6B18.4 alloy, using the parallel geometry, at a fixed microwave frequency of approximately 9.3 GHz in the temperature range 100&#8804;T&#8804;300 K. Detailed lineshape analysis of the observed FMR spectra yields true values of the resonance field, linewidth, damping parameter and splitting factor. The temperature dependence of these quantities is found to be inconsistent with the notion that the observed ferromagnetic behaviour originates from the precipitated crystallites of Ni finely dispersed in the Pauli paramagnetic Ni-B amorphous matrix. By contrast, the present results substantiate their earlier claim that the weak ferromagnetism is an intrinsic property of this alloy