Hall Effect in the Carbides of Transition Metals

Measurements have been made of the electrical resistivity and the Hall constant of the carbides of the fourth and fifth group transition metals at room temperature in order to clarify the electronic structure of these compounds. The Hall coefficients are of the order of -10 -3 coul -1 cm 3 for the fourth group carbides and of -10 -4 coul -1 cm 3 for the fifth ones. Calculating the concentrations of the conduction electron on the basis of the one-band approximation, it was found that the conduction band may be almost empty for the fourth group carbides and may be occupied by about one electron per chemical formula unit for the fifth ones. The results may suggest that all these carbides have similar band structures to each other.