The calculation of the electron density of states in transition metal borides with narrow bands

Abstract

The many-electron Hubbard model which takes into account the influence of electron scattering with spin a on electrons with spin 3̄σ and also dynamic processes which lead to the broadening of resonance levels is discussed. Neglecting electron pair creation and annihilation, we obtained analytical results for the density of states of single electrons N 1( E) and of pairs N 2( E). From the results it follows that in filling a single electron band (m ⩽ 1 2 ) N 1 (E) decreases whereas in filling a pair band (m ⩾ 1 2 ) N 2 (E) increases. The theory we developed is applied to an experimental data analysis of the magnetic susceptibility and the electron specific heat of transition metal paramagnetic borides, carbides and nitrides.