Physical, electrical and magnetic properties of Cr doped Bi2Sr2Ca1Cu2-xCrxOy (Bi-2212) superconductors prepared by laser floating zone technique


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Gun E., Ozkurt B., ÖZÇELİK B. , Madre M. A. , Sotelo A., DIEZ J. C.

JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS, cilt.28, ss.13120-13125, 2017 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 28 Konu: 17
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1007/s10854-017-7145-6
  • Dergi Adı: JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
  • Sayfa Sayısı: ss.13120-13125

Özet

The structural and magnetic properties evolution of Cr-doped Bi2Sr2CaCu2-xCrxOy ceramics (x = 0.0, 0.05, 0.1, and 0.25) have been investigated using XRD, SEM, DC resistivity and M-H measurements. X-ray diffraction studies have shown that all samples are mainly composed of Bi-2212 phase, indicating that Cr can be incorporated in its crystal structure. The microstructure of the highly Cr-doped samples showed that some impurity phases appear, decreasing the conductivity between the grains. T-c (onset) and T-c (offset) have been improved for x = 0.05 Cr doping, while 0.25 Cr doped samples are not superconducting. This behavior can be associated to changes in the hole concentration and/or the magnetic nature of Cr. The magnetic properties indicate that low Cr-doping enhances the loop widths. Additionally, the critical current densities, J(c) , of samples have been calculated by using the Bean's critical state model. It has been found that there are important improvements in J(c) values between 0.2 and 0.9 T applied magnetic fields for 0.05 Cr doped samples.