Sulphur substitution for oxygen in YBa2Cu3O7 ceramics

Tribochemistry of Bulk Zinc Metaphosphate Glasses

“…Similarly to the FT-IR spectra of vitreous phosphate glasses with different compositions reported in the literature [37][38][39][40], the vibrational spectrum of amorphous zinc metaphosphate is characterized by complex peak shapes. The asymmetric peak between 1350 and 1200 cm -1 with a maximum at 1270 cm -1 can be assigned to the v as (PO 2 -) of the Q 2 units and to the v(P=O) of the Q 3 units [38,40,41]. In the region between 1050 and 1150 cm -1 the characteristic stretching mode of the Q 1 units v as PO 2À 3 À Á À Á ; which is usually very intense in IR spectra, was not detected, indicating that the phosphate tetrahedral structure did not undergo any disproportionation reaction as reported in [40].…”

Dependence of Off-Diagonal Components of χ(3) on Substrate Temperature of Epitaxially Grown Vanadyl Phthalocyanine Films

“…The Y-211 particles were found to be oriented with their b 211 -axis parallel to the magnetic induction. Because Y substitution by Dy further enhances the magnetic anisotropy of the cell [18,29], the Dy-211 particles are also expected to be oriented with their b 211 axes parellel to the field direction in the present case.…”

“…The pellet was then introduced into a horizontal furnace. The thermal cycle was similar to that used in previous works [18]. The composite was rapidly heated to 1035 • C and held for 1 h at this temperature.…”

“…The magnetic induction applied during the synthesis process orients the grains [18] such that the majority present their a-b planes as observation planes. Twins can be seen in the majority of the Dy-123 grains but cross-like or triangular-like patterns are not observed in these samples.…”

Chemical Composition and Microstructure of Magnetically Melt-Textured Bi2Sr2Ca0.8Dy0.2Cu2O8−y

“…Several techniques, like melt-texturing growth (Jin, Tiefel, Sherwood, Davis, van Dover, Kammlott, Fastnacht & Keith, 1988;Salama, Selvamanickam, Gao & Sun, 1989;Pollard, McCartney, McN'Alford & Button, 1989;McGinn, Chen, Zhu, Tan, Varasani & Sengupta, 1991;Yoo, Sakai, Talaichi, Higuchi & Murakami, 1994;Murakami, 1994;Salama & Lee, 1994;Sandiumenge, Pinol, Obradors, Snoeck & Roucau, 1994) and creep sintering, (Hendrix, Abe, Borotka, Tien & Caulfield, 1989;Rrgnier, Le Hazif & Chaffron, 1990;Nash, Nash, Shi, Poeppel & Goretta, 1990;Ichinose & Saito, 1991) have been proposed in order to orient the grains in superconducting ceramics, in particular in related YBCO materials. The use of a magnetic field can help the texturing process (de Rango et al, 1991;Cloots et al, 1992). In 2212 structures, grain alignment in a magnetic field results from the magnetic susceptibility anisotropy of calcium substituted by a rare-earth ion, like dysprosium (Chen, Markiewicz & Giessen, 1988;Stassen, Cloots, Rulmont & Ausloos, 1995).…”