Gradually devitrified Co-based metallic glass as a model material for testing Neel's theory of the Rayleigh rule

It is shown in the present paper that gradually devitrified Go-based non-ma gnetostrictive metallic glass is an excellent model material to verify Loui s Neel's theory of the Rayleigh rule. In the course of the calculations, Ne el showed that the parameter p = bH(c)/a (where H-c is the coercivity, a an d b are the coefficients of a quadratic polynomial expressing the Rayleigh rule) is expected to range between 0.6 (hard magnets) and 1.6 (soft). Howev er, the experimental values of this parameter, reported in the literature f or a number of mono- and poly-crystalline magnets, are much greater than th ose expected from the theory presented by Neel tin some cases even by two o rders of magnitude). The measurements, performed for a series of Go-based m etallic glass samples annealed at gradually increasing temperature to produ ce nanocrystalline structures with differentiated density and size of the c rystallites, have shown that the calculated values of the parameter p fall within the range expected from Neel theory.