Small-angle magnetic neutron scattering from Mn and Fe-substituted Co-Ga alloys

The states of magnetic order in Mn- and Fe-substituted CoGa alloys have been studied with the D11A small-angle neutron camera at the ILL, Grenoble. The results are consistent with a model in which the percolation of superparamagnetic clusters is largely responsible for the onset of ferromagnetism, although it also appears, from magnetic measurements, that an average electron concentration parameter is important in defining the magnetic properties of the systems. The results of the investigation are compared with those obtained previously for alloy series formed by substituting Ti, V, Cr and Co for Ga in CoGa.