Temperature dependent magnetic contributions to the high field elastic constants of nickel and an Fe-Ni alloy

• Published in: The Journal of physics and chemistry of solids 1960-01, Vol.13 (1), p.40-55
• Main Authors: Alers, G.A., Neighbours, J.R., Sato, H.
• Format: Article
• Language: English
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/0022-3697(60)90125-6

Since the fundamental interaction between magnetic moments in a ferromagnet makes a contribution to the total energy, there should also be a corresponding contribution to the elastic constants. In order to observe this effect, the elastic constants C 44, 1 2 (C 11−C 12) and 1 2 (C 11+C 12+2C 44) have been measured in nickel and an Fe-30% Ni alloy through their respective Curie temperatures at high enough applied magnetic fields to eliminate the ordinary “Δ E effect” associated with domain wall motion. The intrinsic magnetic interaction which should produce changes in the elastic constants upon passing through the Curie temperature was clearly observed in both materials. The first and the second derivatives of the exchange energy are estimated from these results. Such an interpretation is relatively straightforward for nickel, but the large volume magnetostriction of the Fe-Ni alloy makes the analysis of the data difficult. The measurements on nickel were extended down to 4.2°K while those on the alloy do not go below room temperature because of a possible martensitic transformation of this alloy.