The site preference of Ir, the temperature dependence of magnetic susceptibility and the low-temperature specific heat of β-Mn1-xIrx alloys have been investigated. In Mn1-xIrx alloys, the β-phase exists below x = 0.102. From x-ray diffraction patterns, almost all Ir atoms are substituted at site 1 in the β-Mn lattice. The electronic specific heat coefficient γ is proportional to the Néel temperature TN in the form TN 3/4 in regions of low-Ir concentration. With increasing x, however, the gradual decrease in γ leads to a relative increase in γ from the straight line. Therefore, it is concluded that the magnetic state of the β-Mn1-xIrx alloys varies from a weak itinerant-electron antiferromagnet to an intermediate antiferromagnet with increasing Ir concentration. The point to observe is that the γ versus TN 3/4 plots give a universal line for all the β-Mn alloy systems over the entire concentration range.
ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials