Abstract
Magnetostriction constants, λ100 and λ111, in the state quenched from 700°C of nickel and 3.1, 7.0, 14.2, 18.7 and 25.1 at. % Mn–Ni alloys and those in well-annealed state of 25.1 at. % Mn–Ni alloy have been determined in the temperature range between room and liquid air temperatures. In the quenched state, both constants decrease in magnitude roughly monotonically with increasing Mn content in this temperature range. It seems, however, that each of the magnetostriction constants vs. composition curves at temperatures near liquid air temperature has an inflection point at about 5 at. % Mn. Temperature dependence of the magnetostriction constants in the quenched state is roughly the same in all cases irrespective of the composition. Well-annealed Ni3Mn alloy has fairly large negative magnetostriction constants, which decrease in magnitude rather rapidly with increasing temperature, suggesting the occurrence of the change in their signs well below the Curie temperature. The compositional dependence of the magnetostriction constants in disordered Ni–Mn alloys and the magnitude of the magnetostriction constants of ordered Ni3Mn alloy, are discussed in terms of the atom pair interactions, of which the magnitudes are assumed to vary with atomic magnetic moments.
