Mictomagnetism in a new BaO.Fe2O3.B2O3 glass.

Magnetic properties of disordered oxides with iron and manganese ions

“…Namely, the inverse dc susceptibility is smaller than that anticipated by the Curie-Weiss law at this temperature range. For instance, for the Fe 2 O 3 -TeO 2 glass with 20 mol% of Fe 2 O 3 , the deviation takes place below about 70 K. A similar phenomenon was reported for other oxide glasses containing transition metal ions [2,[13][14][15]. This phenomenon is explainable in terms of the model that magnetic clusters consisting of iron or manganese ions grow with a decrease in temperature just above the spin-freezing temperature and that the magnetic clusters exhibit superparamagnetic or cluster spin glass-like behaviour.…”

Magnetic and structural properties of iron-based oxide glasses, Fe 2O3-BaO-B2O3, from 57Fe Mössbauer spectroscopy

“…In oxide glasses of composition (1x) [0.2 xFe2O3 the occurrence of small iron clusters (dimers, trimers, etc...) has been claimed at low Fe concentration [18], while superparamagnetic behaviour has been demonstrated at high Fe content. d) The crystallization mechanisms, the phase analysis and the evolution of the magnetic properties on crystallization is of intrinsic interest as well as from the point of view of applications. For example, microcrystalline (possibly monodomain) precipitates of barium hexaferrite evolve within a non-magnetic host; such systems may be considered for permanent magnet applications [19,20].…”

“…Experimental. -The amorphous samples were prepared by quenching from the melt between rollers as described previously [19]. The final composition was checked by chemical analysis.…”

“…The non-crystalline nature of the materials was established by X-ray and electron diffraction halos as well as from crystallization on thermal annealing as investigated by DTA and X-ray analyses. The evolution of the bulk magnetic properties on crystallization has been reported separately [ 19,20].…”

Magnetic Properties of Fe Ions in a Silicate Glass and Ceramic

“…Magnetic properties of amorphous materials containing transition metal ions have been extensively studied in the past for both practical and fundamental reasons [1][2][3][4][5][6]. Oxide glasses, specifically those containing Fe 2 O 3 , have been the subject of numerous publications due to their interesting magnetic, structural, and optical properties [7][8][9][10][11]. However, little work has focused on a comparative study of the magnetic properties of the glass and the glass ceramic obtained by heat treatment of the parent glass.…”