Magnetic amorphous alloys obtained by rapid quenching of the melt are excellent soft magnetic materials with a wide range of technological applications. They also represent a significant challenge to the scientific understanding of magnetic materials, since most of the existing theories of solids assume lattice periodicity. For these reasons, the magnetic and other properties of amorphous alloys have been very actively studied over the last decade. In recent years increasing attention has been directed to the fundamental understanding of the structural, thermal and magnetic properties of the amorphous alloys. It is not only scientifically but also technologically important to achieve such an understanding, since the amorphous alloys are, in many respects, so different from conventional crystalline magnetic materials. The author attempts to summarise recent progress in research on magnetic amorphous alloys and critically assesses the present level of understanding of this new class of magnetic materials, focusing mostly on the transition-metal-metalloid glasses. He starts with a review of early developments and a discussion on the nature of glasses and glass formation and proceeds to an extensive discussion of their atomic structure, both from the experimental and theoretical points of view.

https://iopscience.iop.org/article/10.1088/0034-4885/47/12/002/pdf

Magnetic amorphous alloys: physics and technological applications

After some introductory comments on materials classification and a brief historical outline, this review seeks to identify those fundamental physical phenomena that underlie the major technical properties of ferromagnetic amorphous alloys. Those phenomena are reviewed and an attempt is made to compare existing data and, where possible, to synthesize new perspectives. A fundamental approach is taken in the sense that we move from consideration of the local atomic structure to its consequences for the electronic structure and from the electronic structure finally to the physical properties it determines. We focus on the aspects of the structure‐property sequence that set amorphous metallic alloys apart from their crystalline counterparts. Such a review would be incomplete without addressing the new issues and insights raised by the discovery of the quasicrystalline state. The very existence and better understood atomic arrangements of quasicrystals help to define and illuminate their amorphous cousins.

Physics of ferromagnetic amorphous alloys

Induced magnetic anisotropy and change of the magnetostriction by current annealing in Co-based amorphous alloys

The influence of tensile stress annealing on the magnetic properties of amorphous alloys is reported for ribbons belonging to the pseudo ternary system (FeCoNi) 75 Si 15 B 10 . Ribbons of compositions (Co 1-x Fe x ) 75 Si 15 B 10 are susceptible to stress annealing in the whole composition range 0 \leq x \leq 1 . A very large easy ribbon axis anisotromy can be produced in the range 0.2 \leq x \leq 0.7 whereas the largest hard ribbon axis anisotropy is producable in the composition range around x=0.15. Ribbons of compositions [CO 1-x (Fe 0.5 Ni 0.5 ) x ] 75 Si 15 B 10 are found susceptible to stress annealing only in the range 0 \leq x \leq 0.7 . In all the compositions the induced easy ribbon axis anisotropies are irreversible whereas the hard ribbon axis anisotropies are recoverable with activation energies ≥ 1.55 eV.

Effects of longitudinal and torsional stress annealing on the magnetic anisotropy in amorphous ribbon materials

We present the first direct evidence of structural anisotropy due to anelastic polarization produced by mechanical creep, in the form of the anisotropic diffraction intensities observed by energy dispersive x‐ray diffraction method. We suggest that this structural anisotropy is the origin of the creep‐induced magnetic anisotropy.

Magnetic and structural effects of anelastic deformation of an amorphous alloy

Magnetic anisotropy in (Fe, Co)75Si15B10 and (Fe0.11Co0.89)72Mo3Si15B10 metallic glass ribbons, induced by constant stress and constant strain annealing

L.K. Hansen

Papers

Magnetic anisotropy in (Fe, Co)75Si15B10 and (Fe0.11Co0.89)72Mo3Si15B10 metallic glass ribbons, induced by constant stress and constant strain annealing