Pressure Effect on Electronic Band Structure of NiAs-Type CrTe

Pressure influence on the electronic band structure of NiAs-type CrTe is studied for nonmagnetic, ferromagnetic and antiferromagnetic states by using a self-consistent LAPW method. The total energy is calculated as a function of the lattice spacing a, keeping the ratio c/a as the observed value. The ferromagnetic state is stable energetically among three states for a > 3.83 A. For a < 3.83 A, the energy of antiferromagnetic state becomes lower than that of ferromagnetic state. Therefore pressure-induced ferromagnetic→antiferromagnetic transition is expected at about 20 GP. For the ferromagnetic state, which is realized below T_C = 340 K, the theoretical lattice spacing a is obtained as 4.180 A, which agrees fairly well with the observed one (a_obs = 3.981). The magnetic moment arises from mainly Cr-site and it is remarkably reduced by the pressure as observed. A small magnetic moment is induced at Te-site in the direction antiparallel to the moment at Cr-site.