Temperature dependence of hysteresis loops and AC-susceptibility of as-cast and annealed Nd60Fe30Al10 hard magnetic alloy

Rare earth based bulk metallic glasses

“…The hard magnetism doesn't change significantly with annealing around T g but usually disappear when the samples are completely crystallized [9,13]. Although it is generally accepted that the large coercivity is attributed to a variety of different metastable phases (or clusters) and microstructure, the interplay between the local structures and magnetism remains controversial [9][10][11][12][13][55][56][57][58][59][60].…”

“…Nano scale clusters consisting of Nd and/or transitional metals are generally observed by high resolution transmission electron microscopy, Mössbauer spectra measurements, magnetic and resistance measurements, and isothermal calorimetry investigation, etc., in Nd-and Pr-based glasses [9][10][11][12][13][55][56][57][58][59][60][61][62][63][64][65]. Schneider et al attributed the intrinsic composite structure to a phase separation process taking place in the melt or the supercooled liquid state [55][56][57].…”

“…Besides the paramagnetic phases, the grains boundaries, surfaces and magnetic inhomogeneities can play an important role as pinning sites of domain walls. The strong domain wall pinning mechanism (the pinning criterion is satisfied when: a » d 2 , where a is the lateral area of a single pin and d is the wall width [65]) has been proved in these Nd-based alloys from the temperature dependence of coercivity [55][56][57][58][59][60]69]. This is because that the condition of large impediments and narrow domain walls (small d) are easily favored by the inhomogeneous structure and the large RMA in the Ndbased alloys.…”

Microstructure and magnetic property of Fe53Nd37Al10 alloy

“…Table 1 summarizes the magnetic properties of the Nd-based amorphous alloy [11] and the Fe 53 Nd 37 Al 10 alloy studied. To explain the hard magnetic properties of Nd-based bulk amorphous alloys, magnetic exchange coupling interaction between metastable magnetic ordered clusters with large random anisotropy [3,4], or the pinning of domain walls [5,6] has been suggested. In order to interpret the coercivity mechanism of the Fe 53 Nd 37 Al 10 ribbons, the microstructure of the Fe 53 Nd 37 Al 10 as-cast sheet and melt-spun ribbons will be observed by TEM and HRTEM.…”

“…The hard magnetic property of the bulk amorphous form of materials is attracting a number of researchers [1][2][3][4][5][6] by virtue of both the application potential and the nature of the hard magnetic mechanism. However, the low saturation magnetization and remanence of Nd-Fe-Al alloy and the high cost of rare earths restrict its application.…”