Two Ferromagnetic Phases in Spin-Fermion Systems
Abstract
We consider spin-fermion systems which get their magnetic properties from a system of localized magnetic moments being coupled to conducting electrons. The dynamical degrees of freedom are spin- operators of localized spins and spin-1/2 fermi operators of itinerant electrons. We develop modified spin-wave theory and obtain that system has two ferromagnetic phases. At the characteristic temperature T* the magnetization of itinerant electrons becomes zero, and high temperature ferromagnetic phase (T*<T<T_C) is a phase where only localized electrons give contribution to the magnetization of the system. An anomalous increasing of magnetization below T* is obtained in a good agrement with experimental measurements of the ferromagnetic phase of UGe2.
Cite
@article{arxiv.0709.1759,
title = {Two Ferromagnetic Phases in Spin-Fermion Systems},
author = {Naoum Karchev},
journal= {arXiv preprint arXiv:0709.1759},
year = {2009}
}