On explanation of elasticity and thermal expansion invar anomaly
Abstract
In the temperature range 77-1000 K magnetization, magnetic and magnetostrictional susceptibility, the elastic modulus and the coefficient of thermal expansion of Fe 65Ni 35- xCr x quasi-binary alloys in the "Invar" range of the compositions were investigated. The study established the existence of a linear relationship between spontaneous magnetostriction, ω m, and the "exchange" contribution to the elastic modulus, Δ EA, and the square of spontaneous magnetization, M2s. Also, it turned out that the values of the magnetovolume C1 = ω m/ M2s and magnetoelastic C2 = Δ EA/ω m coefficients are virtually independent of the composition. The fact that a change of M2s, in a unique fashion, determines the magnitude of spontaneous magnetostriction and of the "magnetic" contribution to the elastic modulus in the state of technical saturation, is of major importance of elucidating the nature of Invar anomalies.
- Publication:
-
Journal of Magnetism and Magnetic Materials
- Pub Date:
- August 1985
- DOI:
- 10.1016/0304-8853(85)90006-X
- Bibcode:
- 1985JMMM...51...98D