ITINERANT MAGNETISM AND ELECTRONIC-PROPERTIES OF FEGE2

The electronic and magnetic structure of tetragonal FeGe2 is determined using the local spin-density functional approximation and the ASW method to solve the band-structure problem self-consistently. The calculations reveal that the collinear antiferromagnetic structure-in contrast to a non-collinear one-has the lowest total energy and seems the most preferable candidate for the low-temperature ground-state phase of FeGe2 in agreement with recent neutron diffraction experiments. The calculated Fermi surface cross-sections and cyclotron masses are in good agreement with the DHVA experimental data. From the DHVA and heat capacity data together with the results of band-structure calculations the average value of the electron-phonon interaction constant lambda approximately equal to 0.5 has been deduced for FeGe2. For the alternative non-collinear model we obtained a higher value of the total energy and poor agreement with the DHVA experiment.