Improvement in superconductivity of TlBa2CaCu2Oy system by introduction of oxygen loss
1990; Elsevier BV; Volume: 170; Issue: 5-6 Linguagem: Inglês
10.1016/0921-4534(90)90014-6
ISSN1873-2143
AutoresSatoru Nakajima, Masae Kikuchi, Yasuhiko Syono, K. Nagase, Takeo Oku, Norio Kobayashi, Daisuke Shindo, K. Hiraga,
Tópico(s)Inorganic Fluorides and Related Compounds
ResumoThe Tc and oxygen content of TlBa2CaCu2Oy have been investigated by quenching experiments, in which the heat-treated samples were dropped into liquid nitrogen. The oxygen loss, v, of TlBa2CaCu2Oyo − v was determined by thermogravimetry in a nitrogen atmosphere using an oxygen-annealed specimen of TlBa2CaCu2Oyo and also by measurements of the weight differences before and after quenching. Tc increased from 80 K of the oxygen-annealed specimen up to about 110 K with increasing oxygen loss up to v = 0.035 by annealing at 500°C in a nitrogen atmosphere. Judging from the high Tc above 110 K achieved by a small oxygen loss about v = 0.035, the as-sintered oxygen-annealed TlBa2CaCu2Oyo specimen was in the over-doping state and probably has an oxygen vacancy of 7 − yo0.
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