Some modifications and applications of the Pauling theory of ferromagnetism

Abstract

The Pauling theories of ferromagnetism and metal structure are discussed and compared with other theories. The results of Pauling are derived with the inclusion of previously neglected temperature effects. The metallic band structure assumed by Pauling is also modified and the modification is shown to lead to better agreement with the results of previous investigations. The ferromagnetic alloys are studied with the use of the Pauling theory. It is demonstrated that the simple theory is inadequate for the treatment of alloys, and an improved model is proposed. Calculations based upon this model provide qualitatively correct predictions of the behavior of the Curie temperature of many ferromagnetic alloys. Explanations of the abnormal behavior of the iron-vanadium and nickel-chromium alloys are offered. The effects of non-uniform electron distribution in ferromagnetic crystals are considered. An expression for the Curie temperature is derived. If reasonable values of the parameters which describe the non-uniformity are inserted in this expression, the result is an increase in the predicted Curie temperature of nickel and a decrease in that of iron, both of which are improvements. Some methods of estimating the values of the parameters are discussed. It is concluded that the Pauling theory, with appropriate modifications, will accurately describe ferromagnetic behavior.