Hysteresis loops for a bulk ferromagnetic by Heisenberg model
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hysteresis loop
ferromagnetism
paramagnetism
Curie temperature
Curie point
magnetisation curve
Curie — Weiss law
transcedental equation
Abstract
In a framework of Heisenberg theory, that link quantum-statistical description taking Gauss distribution into account, explicit form is obtained by permutations group theory, the division paramagnetic/ferromagnetic is studied. The magnetization curves are built for a given set of parameters, such as exchange integral, number of closest neighbours and temperature. In a special range of the parameters a transition from unique solution of the resulting Heisenberg equation to multi-valued is observed. For this case exemplary hysteresis loops are built. The expression for Curie temperature allows to evaluate the exchange integral and proceed into temperature range above the critical temperature.