Magnetic Properties of Bulk Metallic Glasses

Abstract

The discovery and large scale investigation of rapidly solidified alloys have brought to light, in the last three decades a new scenario in basic and applied magnetism. With a range of composition and microstructural states unavailable to conventional materials, the rapidly quenched alloys have in fact demonstrated unprecented versatile properties, provide unique opportunities in applications and enlarged the domain of physical theories. In this paper, the basic magnetic features of two classes of magnetic bulk metallic glasses, soft and hard magnetic alloys, will be briefly highlighted

Application of the Stoner–Wohlfarth model with interaction for the determination of the saturation magnetisation, anisotropy field, and mean field interaction in bulk amorphous ferromagnets

“…There has been much interest in the origin of the hard magnetic properties displayed by bulk amorphous ferromagnets. Some studies have explored the applicability of the random anisotropy model to these materials, whilst others have given credence to a strong-pinning model, which includes thermal activation effects, as it provides a good explanation of the temperature dependence of the coercivity [8][9][10][11][12][13][14][15][16].…”

Temperature dependence of the coercivity in Nd60Fe30−xCoxAl10, x=0 or 10, and Pr58Fe24Al18 bulk amorphous ferromagnets

“…The mechanism responsible for coercivity in these materials remains unresolved, and much discussion continues as to its origin. A number of mechanisms have been proposed, including a random anisotropy model [5,15], the strong coupling of the nanocrystalline clusters to a ferromagnetic phase in an exchange-bias type manner [9], and a strong pinning model due to Gaunt [16,17]. A feature of the strong pinning model, which includes thermal activation effects, is the predicted behaviour of the coercivity as a function of temperature [16].…”

Origin of high glass forming ability of Y-containing FeB-based alloys

“…Due to high mechanical strength, cheap cost and excellent soft magnetic properties, great efforts have endeavored to develop Febased bulk metallic glasses (BMGs) [1,2]. Minor addition of several particular elements, such as Co, Mo, Nb and Y, was reported to be an effective way to enhance glass forming ability (GFA) of Febased BMGs [3][4][5][6][7][8][9], while its origin still remains an open question.…”

“…In this work, we select Fe-Y-B system, as a prototype, to investigate the correlation of GFA with its atomic structure by using extended X-ray absorption fine structure (EXAFS), together with differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Two questions are addressed: (1) why can tiny Y addition enhance GFA and (2) why does more Y addition (>7 at.%) deteriorate GFA.…”