ISSN:
1432-0630
Schlagwort(e):
PACS: 74.70; 61.12; 64
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Maschinenbau
,
Physik
Notizen:
3 Ox with both orthorhombic and tetragonal structure were synthesized using different heat treatments. From each type, a series of oxygen-depleted samples, denoted as “O” and “T”, with oxygen contents 6.5〈x〈7.0 were prepared by annealing in argon at different temperatures in the range 300–550 °C. For O- and T-samples, superconductivity vanishes below x≈6.8 and x≈6.6, respectively. While T-samples show a continuous variation of both Tc and the unit-cell volume with x, O-samples show coinciding anomalies in these dependences. In all cases, the oxygen loss with respect to fully oxygenated samples was determined by both weight measurements (δw) and iodometric titration (δt) With T-samples, δw and δt are in good agreement, whereas with O-samples considerable discrepancies between these values were found. These disparities in the properties of O- and T-samples may be related to differences in the oxygen sublattice.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/s003390050572
