ANOMALIES OF THERMAL-EXPANSION IN AG DIFFUSION DOPED BIPBSRCACUO SUPERCONDUCTORS

ALTUNBAS M., DZHAFAROV T., KUCUKOMEROGLU T., KOPYA A., GORUR O.

PHYSICA C, vol.249, pp.133-138, 1995 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 249
  • Publication Date: 1995
  • Doi Number: 10.1016/0921-4534(95)00301-0
  • Journal Name: PHYSICA C
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.133-138
  • Karadeniz Technical University Affiliated: Yes

Abstract

Thermal expansion of Ag-Bi1.6Pb0.4Sr2Ca2Cu3Ox structures was measured in the interval 20-830 degrees C using an inductive dilatometer. Two anomalies in the thermal-expansion curves of samples were discovered: a decrease in length Delta L/L on heating (740-810 degrees C) and an increase in Delta L/L on cooling (810-660 degrees C). Changes of composition, structure and electrical properties of Ag doped superconductor caused by heat treatments during thermal-expansion runs were examined using XRD, DTA, optical microscopy and resistivity measurements. A model explaining the observed results was discussed. Thermal-expansion coefficients of Ag doped and undoped BiPbSrCaCuO samples are 7.5 x 10(-6) K-1 (at 60-680 degrees C) and 6.4 x 10(-6)K(-1) (at 30-830 degrees C), respectively.