The effect of calcium substitution in deoxygenated R1-xCaxBa2Cu3O6.1 systems (R = Y, Eu): appearance of superconductivity, insulator to metal transition

Authors
Starowicz, P Sokolowski, J Balanda, M Szytula, A
Citation
P. Starowicz et al., The effect of calcium substitution in deoxygenated R1-xCaxBa2Cu3O6.1 systems (R = Y, Eu): appearance of superconductivity, insulator to metal transition, PHYSICA C, 363(2), 2001, pp. 80-90
Citations number
29
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICA C
ISSN journal
09214534 → ACNP
Volume
363
Issue
2
Year of publication
2001
Pages
80 - 90
Database
ISI
SICI code
0921-4534(20011101)363:2<80:TEOCSI>2.0.ZU;2-G
Abstract
The changes in crystallographic, magnetic, and transport properties with ca lcium substitution in deoxygenated R1-xCaxBa2Cu3O6.1 (R = Y, Eu) system hav e been investigated. The superconductivity is induced at a calcium content of x = 0.26-0.3. However, the induced superconductivity exhibits a low crit ical field. The system R1-xCaxBa2Cu3O6.1 undergoes an insulator to metal tr ansition. The increase in the effective magnetic moment with Ca substitutio n is detected. The crystal structure undergoes slight modifications. Althou gh, the observed variation of crystal structure forced by Ca doping does no t reproduce the structure modifications characteristic of oxygen doping, Th e discussed changes in properties of R1-xCaxBa2Cu3O6.1 should be mainly rel ated to hole doping, observed as an increase in formal copper valence, whic h was confirmed by iodometric titration. (C) 2001 Elsevier Science B.V. All rights reserved.