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Ground state of a system with ferromagnetic s‐f interaction
Author(s) -
Vertogen G.
Publication year - 1968
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.19680250226
Subject(s) - ferromagnetism , ground state , condensed matter physics , diagonal , physics , spin polarization , electron , perturbation (astronomy) , magnetization , polarization (electrochemistry) , quantum mechanics , chemistry , magnetic field , mathematics , geometry
The perturbation expansion is obtained for a free electron gas interacting with a nuclear or ionic spin system via a ferromagnetic s—f‐interaction. No divergent terms appear in the expansion if the unperturbed ground state of the system is assumed to consist of a polarized electron gas and a ferromagnetic spin system. This assumption is made plausible by considering the diagonal part of the perturbation and minimizing the resultant energy with respect to both the polarization of the electron and the structure of the spin system. In this way an energy up to second order in J is also obtained, and this is lower than the R.K.K.Y. result for a ferromagnetic spin system. No corrections to the magnetization of the spin system appear up to first order in J .