Hydrothermal synthesis of a new Bi-based (Ba0.82K0.18)(Bi0.53Pb0.47)O3 superconductor

• Hydrothermal synthesis of new (Ba0.82K0.18)(Bi0.53Pb0.47)O3 simple cubic perovskite compound.
• Superconductivity with Tc ∼ 22.8 K in Ba1−yKyBi1−xPbxO3 system.
• Structural refinement has been performed using synchrotron X-ray diffraction (SXRD) data.
• Similar structural and superconducting stability has been observed up to 600 °C.
• The metallic behavior of this superconductor is confirmed by electronic band structure.

A new type of bismuth-oxide-based superconductor was prepared by a hydrothermal reaction at 240 °C. The synchrotron X-ray powder diffraction pattern reveals a simple perovskite-type structure with a cubic cell of a = 4.28877(1) Å with space group Pm-3¯m. The chemical composition of this cubic perovskite oxide was formulated as (Ba0.82K0.18)(Bi0.53Pb0.47)O3 after structural refinement using synchrotron X-ray powder diffraction and chemical analysis data. The cubic microstructure and compositional homogeneity were confirmed by scanning electron microscopy analysis. This compound exhibited a diamagnetic signal with a shielding volume fraction of ∼64% with an onset of approximately 22.8 K. Its resistivity started to drop at ∼15 K, and zero resistivity was observed below 4 K. The thermal decomposition of this simple perovskite structure started above 600 °C. Finally, the calculated band structure also exhibited metallic behavior at ambient conditions.

We have synthesized a new member of a bismuth oxide based superconductor with Tcmag ∼ 22.8 K by a facile hydrothermal reaction at 240 °C. The chemical composition of this cubic perovskite oxide was presented as (Ba0.82K0.18)(Bi0.53Pb0.47)O3 by structural refinement using synchrotron X-ray powder diffraction and chemical analysis. Thermal decomposition of this simple perovskite structure started above 600 °C.Figure optionsDownload as PowerPoint slide