Nonferromagnetic Cr‐Si‐Mn Invar alloys

To obtaine nonferromagnetic Invar alloys, the physical properties of some Cr‐base dilute alloys are investigated. Cr is an antiferromagnetic metal and its physical properties around the Neel temperature TN are sensibly affected by the addition of solute atoms.It has been found that the antiferromagnetic transition in Cr‐Si alloys is of the first kind. The thermal expansion coefficients of the alloys below TN become very small, showing the Invar characteristic; the INvar region is observed below room temperature and the region occurs at lower temperatures with increasing Si concentration. In Cr‐Mn alloys, TN increases with Mn concentration and the thermal expansion coefficients below TN becom smaller, but their TN are far above room temperature.Taking these results into consideration, the thermal expansivity and the magnetic properties of Cr‐Si‐Mn primary solid solution alloys have been measured. It was found that the alloys are antiferromagnetic showing the Invar characteristic, and the magnetic susceptib...