Man Nie

Influence of carbon content on the lattice variation, magnetic and electronic transport properties in Mn3SnCx

The structural, magnetic, lattice, and electronic transport properties of Mn3SnCx compounds were investigated. Variation in carbon content from 0.6 to 1.2 does not change the crystal structure. With the increasing of x, the magnetic order changes from antiferromagnetic to ferromagnetic, and the transition temperature increases. The lattice constant shrinks around magnetic transition temperature when temperature increases. The total behavior of Mn3SnCx in temperature dependence of resistivity is very complex. For some Mn3SnCx, the temperature coefficient of resistivity is negative in the scope of magnetic order temperature. For other Mn3SnCx, the total behavior is metallic-type, and the resistivity appears an abrupt change.

Investigation of Lattice Contraction in Mn3XN(X=Zn, Cu, Sn)

The Mn3XN(X=Zn, Cu, Sn) compounds and their solid solutions with anti-perovskite structure were prepared by solid state reaction. Their magnetic transition and simultaneous abnormal thermal expansion behaviors were studied by SQUID and variable temperature X-ray diffraction. The lattice contraction was found in Mn3Cu0.5Sn0.5N and Mn3Zn0.5Sn0.5N during the magnetic transition process, however not in pure Mn3XN(X=Zn, Cu, Sn). The mechanism is discussed, combined with the different doping effects. It seems that the lattice contraction behavior is sensitive to the number of valence electrons at the X site in Mn3XN series.