Synthesis and Properties of the Layered Oxycarbonates Sr2-xBaxCuO2(CO3)

✍ Scribed by A.R. Armstrong; H.S. Obhi; P.P. Edwards

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 302 KB
• Volume: 106
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1993.1270

✦ Synopsis

We report here the synthesis and infrared characteristics of the solid solution of the layered oxycarbonates (\mathrm{Sr}{2-x} \mathrm{Ba}{x} \mathrm{CuO}{2}\left(\mathrm{CO}{3}\right)(0 \leq x \leq 2)). Synthesis, under partially enclosed conditions, from ( (\left.\mathrm{Sr}, \mathrm{Ba}^{2}\right) \mathrm{CO}{3}) and (\mathrm{Cu}) ) is observed to give enhanced stability of the oxycarbonate as the partial pressure of (\mathrm{CO}{2}) over the sample appears to retard both the reaction and the subsequent decomposition of the oxycarbonates. Compounds with higher barium content are more stable, in keeping with the considerable stability of (\mathrm{BaC} \mathrm{CO}), with respect to decomposition. The a lattice constant shows an anomalously large increase at high barritm content, accompanied by an anomaly in the Cu-O inplane vibration occurring at around (506 \mathrm{~cm}^{-1}) and an accompanying loss of antiferromagnetic order. Both effects are attributed to the presence of adtitiomal oxygen in the structure of compounds at these stoichiometries, analogous to that found earlier for ((\mathrm{Ba}, \mathrm{Sr}){2} \mathrm{CuO}{3+\delta}) materials. 1993 Academic Press, tnc.