The Tb-123 phase has been synthesized in single-phase form with the composition TbSr2Cu2.7Mo0.3O7 by solid-state reaction route and its phase purity is confirmed by neutron powder diffraction experiments. As-synthesized sample does not show superconductivity down to 5 K. An unusually high antiferromagnetic ordering temperature (TN) of around 7 K is seen for Tb. After 120-atm-O2 post-annealing, bulk superconductivity is achieved in the compound at around 30 K, without any significant effect on TN. To achieve higher oxygen content and higher Tc, the as-synthesized sample is subjected to high-pressure oxygenation (HPO) carried out in a closed cell at 5 GPa and 400 oC in the presence of AgO as an excess-oxygen source. This sample exhibited superconductivity onset at around 80 K with a Meissner fraction of larger than 10 % at 5 K. Our observation of superconductivity at 80 K is the highest Tc to-date among the Tb-123 compounds.
@article{arxiv.cond-mat/0305555,
title = {Superconductivity of up to 80 K for Tb-123 - TbSr2Cu2.7Mo0.3O7},
author = {V. P. S. Awana and H. Kishan and E. Takayama-Muromachi and T. Watanabe and M. Karppinen and H. Yamauchi and S. K. Malik and W. B. Yelon and V. Ganesan and A. V. Narlikar},
journal= {arXiv preprint arXiv:cond-mat/0305555},
year = {2016}
}