Weak itinerant antiferromagnetism: Two-band nesting model and effect of spin fluctuations

In this work we calculate the effect of spin fluctuations on a weak itinerant antiferromagnetism of transition metals alloys described by a nesting model with the presence of both the nesting parts at the Fermi surface and the so-called ''electron reservoir''. It is shown that the presence of ''electron reservoir'' with the large exchange enhancement factor of spin fluctuations leads to a decrease of the Neel temperature as compared to its value estimated in the mean-field approximation. A mechanism of magnetic order destruction, which is not associated with the scattering of the nesting parts electronic states on the ''electron reservoir'' spin fluctuations, is discussed. An extensive discussion of the thermophysical properties for this model, and of the physical and experimental implications of the results are presented.