Spin glass transition and hyperfine parameters in FeO-Al₂O₃-SiO₂glasses

Spin glass-like antiferromagnetic interactions in iron phosphate glasses

“…1 by arrows. The parameters in Table 1 are all of the same order of magnitude compared with other amorphous spin glass-like systems [5,[8][9][10][11][12]. The difference in the field-cooled and zero-field cooled susceptibilities (Fig.…”

“…Thus it is apparent that some transition occurs at the cusp temperature (hereafter referred to as T f , the spin freezing temperature). This transition has been widely studied [3][4][5][6][7], although its nature is still not clear.…”

“…Various iron-containing oxide glasses display the phenomenon of spin freezing at low temperatures, for instance sodium germanates and sodium silicates [8], aluminosilicates [5,9,10], and phosphates [11,12].…”

Magnetic properties of disordered oxides with iron and manganese ions

“…The values of m 0 , E a /k B , and T 0 are 10 7 Hz, 9.4 K, and 8.7 K, respectively. The Vogel-Fulcher law has been applied to the frequency dependence of spin-freezing temperature for oxide glasses [16] as well as canonical spin glasses [17]. Although the physical meaning of T 0 is not clear, it corresponds to intercluster interaction or a temperature at which the spin-freezing takes place over the whole glass structure according to Shtrikman and Wohlfarth [18,19].…”

Magnetic phases of imperfectly crystalline Co2SiO4

“…On the other hand, there are studies on specimens containing metal-oxide particles embedded in silica, M 2 O 3 ±SiO 2 in which a variety of magnetic responses are reported [7]. For composites with Fe in silica, e.g., FeO±Al 2 O 3 ±SiO 2 , the magnetization below 20 K was observed to dier when the Journal of Non-Crystalline Solids 273 (2000) 277±281 www.elsevier.com/locate/jnoncrysol temperature was increased or decreased [8,9]. This thermal irreversibility was assumed by the authors to be indicative of a spin-glass property.…”