CPA Treatment of the Hubbard Model with Intra-Atomic Exchange Interaction

The Hamiltonian for a completely degenerate d-band including intra-atomic Coulomb and exchange interactions is derived and studied using the alloy analogy method. Green's function, the magnetic susceptibility and a criterion for the appearance of ferromagnetism are obtained by this method. The dependence of the magnetization on the exchange constant and on the number of electrons per atom is calculated for strong Coulomb correlation and for the uncorrelated case. It is shown that Coulomb correlation of any strength leads to a decrease of the exchange interaction constant needed to produce ferromagnetism and additionally to a change in the shapes of the magnetic dependences for (and only for) weakly ferromagnetic metals. [Russian Text Ignored.]

[1]  A. V. Vedyaev,et al.  On the instability of paramagnetism in the extended Hubbard model , 1975 .

[2]  W. Nolting.  Dynamical Susceptibility for Interacting Electrons in a Narrow Energy Band , 1974, January 1.

[3]  M. Zuckermann.  The Magnetic Properties of Disordered Transition Metal Alloys Using the Coherent Potential Approximation and Related Methods , 1974 .

[4]  F. Sacchetti,et al.  Coherent-potential approximation with orbital degeneracy in ferromagnetic alloys an application to ferromagnetic Co-Ni alloys in f.c.c. phase , 1974 .

[5]  J. Meyer,et al.  Zero-Temperature Magnetic Properties of the Hubbard Model with Infinite Coulomb Repulsion , 1973 .

[6]  S. Nara,et al.  Solvable Decorated Ising Model with Superexchange Interaction , 1973 .

[7]  H. Fukuyama,et al.  Strong Correlations in Disordered Systems , 1973 .

[8]  J. Schneider,et al.  Intra‐ and Interatomic Electron Correlation in an Orbitally Nondegenerate Narrow Band , 1973 .

[9]  J. Schneider,et al.  Renormalization of the Bandwidth by Interatomic Interaction , 1973 .

[10]  H. Hasegawa,et al.  Calculation of Electronic Structure of Ni Base fcc Ferromagnetic Alloys in the Coherent Potential Approximation , 1972 .

[11]  J. Schneider,et al.  Electron Correlation in a Doubly Degenerate Band , 1972 .

[12]  J. Yamashita,et al.  Band Theory of Antiferromagnetism in 3d f.c.c. Transition Metals , 1971 .

[13]  J. Callaway,et al.  Band Structure, Spin Splitting, and Spin-Wave Effective Mass in Nickel , 1970 .

[14]  Scott Kirkpatrick,et al.  Single-Site Approximations in the Electronic Theory of Simple Binary Alloys , 1968 .

[15]  J. Callaway.  Spin Waves in a Model Ferromagnetic Metal , 1968 .

[16]  C. Windsor,et al.  Susceptibility and Intra-Atomic Exchange in Nickel , 1968 .

[17]  N. D. Lang,et al.  Interpolation Scheme for Band Structure of Noble and Transition Metals: Ferromagnetism and Neutron Diffraction in Ni , 1966 .

[18]  J. Hubbard.  Exchange splitting in ferromagnetic nickel , 1964 .

[19]  J. Hubbard,et al.  Electron correlations in narrow energy bands III. An improved solution , 1964, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[20]  J. Hubbard,et al.  Electron correlations in narrow energy bands. II. The degenerate band case , 1964, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[21]  J. Hubbard.  Electron correlations in narrow energy bands , 1963, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[22]  J. C. Slater.  The Ferromagnetism of Nickel. II. Temperature Effects , 1936 .

[23]  John C. Slater,et al.  The Ferromagnetism of Nickel , 1936 .