科研之友
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摘要
Using density-functional theory we investigate the evolution of the magnetic ground state of NbFe2 due to doping by Nb-excess and Fe-excess. We find that nonrigid-band effects due to the contribution of Fe d states to the density of states at the Fermi level are crucial to the evolution of the magnetic phase diagram. Furthermore, the influence of disorder is important to the development of ferromagnetism upon Nb doping. These findings give a framework in which to understand the evolution of the magnetic ground state in the temperature-doping phase diagram. We investigate the magnetic instabilities in NbFe2. We find that explicit calculation of the Lindhard function, chi(0)(q), indicates that the primary instability is to finite q antiferromagnetism driven by Fermi-surface nesting. Total-energy calculations indicate that q=0 antiferromagnetism is the ground state. We discuss the influence of competing q=0 and finite q instabilities on the presence of the non-Fermi-liquid behavior in this material.
- 出版日期2010-10-25
