Transport and structural properties of the Ho1Ba2Cu3O9−δ superconductor

Abstract

The compound Ho₁Ba₂Cu₃O_9−δ has been found to be a high T_c superconductor. The onset of the superconducting transition is 88 K with zero resistance achieved at 87 K. The x‐ray diffraction spectrum of this material shows it to be a single‐phase perovskite similar to the Y₁Ba₂Cu₃O_9−δ compound but different from the K₂NiF₄ perovskite which is believed to be the superconducting phase for the La_2(1−x) Ba_2xCuO_4−δ system. Possible oxygen deficiencies in several of the unit cell planes are discussed. The room‐temperature resistance, the superconducting onset temperature, and the emergence of the single phase all depend upon the sample preparation firing conditions.