Role of interfaces in changes of magnetic properties and magnetoresistance of Alfenol 16

摘要

Influence of interfaces, predominantly grain boundaries and high dislocation density regions, on magnetic properties (parameters of hysteresis loops and Mossbauer spectra) and magnetoresistance, is studied on the Alfenol 16 alloy. The amount of interfaces was changed by heat and mechanical treatments. Hysteresis loops differ in polarization values near the saturation as well as in shape. In the samples with D0/sub 3/ superstructure hard approach to saturation indicates ferrimagnetic like behaviour. Changes in the low held part of magnetoresistance curves depend on kind and amount of interfaces: conduction electrons scatter on domain walls being closely bound to interface objects. The slope of the magnetoresistance curve for high fields is in correlation with the degree of D0/sub 3/ order: Al atoms occupying lattice positions out of the D0/sub 3/ order disturb the spin orientation. It increases the resistivity, in comparison with other centres of scattering of conduction electrons removable by external field, quite substantially.