The electrical resistivity, magnetic and low-temperature specific heat measurements, and theoretical calculations for L10-type MnPd alloy system were carried out in a wide range of composition from 40 to 60% Pd. In the present antiferromagnetic alloy system, the highest Néel temperature TN was observed in the vicinity of 53% Pd concentration, deviating from the equiatomic concentration. This behavior was also conformed by the theoretical calculations for the effective exchange constant J0 which gives the value of TN. In the temperature dependence of electrical resistivity for the L10-type MnPd alloys, a characteristic behavior of a hump just below TN was observed, which is associated with the pseudo-gap-type antiferromagnets. In addition, the value of the electronic specific heat coefficient γe is significantly small below 1 mJ mol-1 K-2 above 50% Pd, reflecting the very low density of states at the Fermi energy EF. The linear relation between the magnetic moment and the Pauling valence has been confirmed in the L1 0-type Mn alloy systems, together with that of other Mn alloy systems. The present several results strongly imply that the characteristic electronic structure with the pseudo-gap and the Pauling valence (PV) associated with the covalent bonding state is closely interrelated in the L1 0-type Mn alloy systems.
- Electronic specific heat coefficient
- L1-type structure
- Pauling valence
- The Néel temperature