Magnetic and electrical/thermal transport properties of Mn-doped M_n+1AX_n phase compounds Cr_2−xMn_xGaC (0 ≤ x ≤ 1)

In this paper, we report the effects of partial substitution of Mn for Cr on the structural, magnetic, and electrical/thermal transport properties of M_n+1AX_n phase compounds Cr_2−xMn_xGaC (0 ≤ x ≤ 1). As a result, the unit cell volume and the thermal conductivity decrease while the resistivity increases with increasing x. Interestingly, the magnetism of Cr_2−xMn_xGaC changes from the nonmagnetic Cr₂GaC (x = 0) to the ferrimagnetic CrMnGaC (x = 1). In order to shed light on the discrepancy observed between Hall coefficient and Seebeck coefficient of Cr₂GaC, the electrical conductivity, Hall coefficient, and magnetoresistance are analyzed within a two-band model. Furthermore, an upturn is observed in low-temperature specific heat of Cr_2−xMn_xGaC, which may be related with the magnetic Mn dopant.