Premium
Spin‐free quantum chemistry. XIV. The infinite interaction range model for ferromagnetism
Author(s) -
Matsen F. A.,
Cosgrove J. G.,
Picone J. M.
Publication year - 1973
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560070605
Subject(s) - magnetization , extrapolation , ferromagnetism , condensed matter physics , partition function (quantum field theory) , thermodynamic limit , heisenberg model , chemistry , spin (aerodynamics) , spontaneous magnetization , magnetic susceptibility , ising model , phase transition , physics , magnetic field , quantum mechanics , thermodynamics , mathematics , mathematical analysis
The infinite interaction range model ( IIRM ) for ferromagnetic systems is presented in its spin‐free formulation. In this formulation the states are labelled by partitions which provide a natural variable for thermodynamic computation. We have extended the calculations of Kittel and Shore by computing to a practical thermodynamic limit ( N ∼ 100,000). The heat capacity, magnetic susceptibility and the magnetization of the first two functions exhibit a critical temperature while the magnetization is zero at zero field for all temperatures. Spontaneous magnetization is obtained by linear extrapolation from high field or equivalently by a polarized partition function. Relationships are explored among IIRM , the Heisenberg model and the mean field model. Application to IIRM of the Yang‐Lee condition for a phase transition yields a critical temperature identical to that obtained by the direct calculation.