Surface morphology and crystal structures of as-grown BiSrCaCuO thin films prepared by RF magnetron sputtering from three targets

• Published in: Japanese Journal of Applied Physics Vol. 28; no. 9; pp. 1586 - 1592
• Main Authors: KURODA, K, KOJIMA, K, TANIOKU, M, YOKOYAMA, K, HAMANAKA, K
• Format: Journal Article
• Language: English
• Published: Tokyo Japanese journal of applied physics 01.09.1989
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Solid surfaces and solid-solid interfaces; Surface and interface dynamics and vibrations; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Crystal growth; Superconducting materials; Magnetron; Bismuth Calcium Copper Strontium Oxides Mixed; Radiofrequency sputtering; Thin film
• DOI: 10.1143/jjap.28.1586
• ISSN: 0021-4922

As-grown superconducting BiSrCaCuO thin films were grown at 650°C on MgO(100) substrates by RF magnetron sputtering from three targets. The substrate was rotated over the three targets: Bi 3 Sr 2 Ca 2 Cu 3 O x , Bi 2 Sr 3 Ca 3 Cu 3 O x and Bi 2 Sr 2 Ca 2 Cu 4.5 O x . By adjusting the staying time of the substrate over each target, it was possible to precisely control the chemical composition of the thin film. This paper describes the superconducting properties, surface morphology and crystal structures of sputtered films formed by varying the staying time. X-ray diffraction measurement showed that the crystal structure could be changed by varying the staying time. The film with the optimum composition showed zero resistivity at 75 K and had an exceedingly smooth surface. This film had the mixed phase which is considered to be a stacked structure consisting of a high- T c phase and a low- T c phase.