The influence of the temperature treatment on the Nd2-xCexCuO4-y crystals surface

✍ Scribed by T. Klimczuk; W. Sadowski; J. Szmytkowski

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 379 KB
• Volume: 54
• Category: Article
• ISSN: 0042-207X
• DOI: 10.1016/s0042-207x(98)00436-9

✦ Synopsis

Superconductivity in the Nd

\V Ce V CuO \W (NCCO) system can be obtained in a narrow range of the cationic and anionic stoichiometry. One possibility to enlarge this range is lowering oxygen concentration with preservation of the ¹ structure. The surface morphology of Nd Ce CuO \W after heat treatment in a reducing atmosphere (argon) in the wide temperature range from 890 to 1120°C was studied using atomic force and scanning electron microscopes. It was observed that the ''as-grown'' Nd Ce CuO \W single crystals the surfaces are flat with steps about two lattices parameters while a high-temperature reduction process (¹*1080°C) leads to a considerable deviation from the flatness. Elongated, rectangular crystalline features of the height between 30 and 120 nm can be observed. EDAX investigations showed that the objects are Nd \V Ce V Cu \X O \W , with z+0.3. It should be noted that NCCO crystal encapsulated in polycrystalline material and annealed at the same temperature for 48 h did not show any decomposition effects.