Magnetic properties ofβ-FeSi2single crystals

The results of magnetization and magnetic susceptibility measurements on $n$- and $p$-type $\beta$-Fe${\mathrm{Si}}_2$ single crystals are presented. The magnetic susceptibility in the studied crystals are determined by the temperature-independent contribution from the lattice, lattice defects and/or neutral impurities, and by the temperature-dependent parts due to paramagnetic centers as well as due to the carriers excited thermally at high temperature. The temperature variation of the paramagnetic terms are in agreement with the Curie-Weiss law. The values of the Curie-Weiss temperatures, activation energy of the donor and acceptor levels, and the upper (lower) limit of the density of state electron (hole) effective masses were estimated.