Magnetic properties of amorphous Co-Mn-B alloys

The effects of B and Mn contents on the magnetic moment and the Curie temperature of Co-Mn-B amorphous alloys have been studied in a wide range of B and Mn concentrations. The magnetic moment at 4.2K decreases monotonically with increasing Mn content for the alloys with low B content, while it increases initially and then decreases similarly to the low B alloys for the alloys with high B content. Ferromagnetic moments vanish at about x=0.4 irrespective to B content. The Curie points also reach zero absolute temperature near the same Mn content. These Mn and B composition dependences of magnetic moment are analysed on the basis of the local environment model.