Galvanomagnetic Properties of Cobalt Monosilicide and Alloys Based on It

The Hall coefficient and conductivity of cobalt-monosilicide CoSi, as well as Co_{1 –x}Fe_xSi and Co_{1 –x}Ni_xCo alloys with iron and nickel contents of up to 8 and 5 at %, respectively, are investigated. The temperature dependences of the Hall coefficient and conductivity are measured in the temperature range of 77–800 K. Theoretical interpretation of the experimental dependences is based on two different models of the electronic structure of the compound: a simple two-band semimetallic structure with a small overlap of isotropic parabolic bands and an ab initio electronic structure, containing topological features with multiply degenerate intersections of bands near the Fermi energy.