Effects of carbon content on structural, magnetic, and electrical/thermal transport properties of antiperovskite compounds GaCxFe3

Abstract

In this paper, we report the effects of carbon content on crystal structure, magnetic and electrical/thermal transport properties in antiperovskite compounds GaCxFe3 (0.15 ≤ x ≤ 0.3). Our experimental results indicate that all the physical properties we measured are sensitive to the carbon concentration for GaCxFe3. With decreasing the carbon content x, the Curie temperature (TC), saturated magnetization, and coercive force (HC) increase while the lattice constant, Debye temperature, and resistivity decrease gradually. Further analysis suggests that the serial GaCxFe3 can be a new kind of promising high-temperature soft magnetic material considering their high-TC (∼788 K) and low-HC (∼22 Oe). Interestingly, the low-temperature resistivity exhibits an abnormal semiconducting behavior below a characteristic temperature for each of GaCxFe3 (0.15 ≤ x ≤ 0.3). This abnormality of resistivity may be attributed to a combination of the renormalized electron-electron interaction and the weak-localization. Furthermore, the studies of the thermal transport and the Hall measurement suggest that the type of dominant carriers in GaCxFe3 changes gradually from hole- to electron-type with decreasing x.