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Oxygen Plasma Effects on Zero Resistance Behavior of Yb,Er‐doped YBCO (123) Based Superconductors
Author(s) -
Schäfer Helmut,
Banko Franziska,
Nordmann Jörg,
Voss Benjamin,
Steinhart Martin,
Walder Lorenz,
Rathmann Dirk
Publication year - 2014
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201400131
Subject(s) - yttrium , materials science , analytical chemistry (journal) , oxygen , doping , electrical resistivity and conductivity , superconductivity , spectroscopy , chemistry , condensed matter physics , oxide , metallurgy , physics , optoelectronics , organic chemistry , chromatography , quantum mechanics
Rare‐earth doped YBa 2 Cu 3 O 7– δ samples were synthesized starting from the corresponding oxides Y 2 O 3 , Yb 2 O 3 , Er 2 O 3 , CuO as well as Ba(OH) 2 by heating to 950 °C under air. The doping concentrations were adjusted to 15 % Yb, 7 % Er and 20 % Yb, 15 % Er, respectively, with respect to the yttrium content. The orthogonal phased (123) YBCO ceramics were exposed to an oxygen plasma for 140 and 380 min. Zero resistance temperature ( T c,0 ) was determined by measuring the resistivity‐temperature dependence using a classical four point measurement approach. Under optimal conditions with respect to the material composition and the oxygen treatment an unusual high zero resistance temperature of 97.5 K ( T c,onset ≈ 101 K) was achieved. This represents an increase of T c,0 by 7.5 K. The oxygen treatment could not be monitored by IR spectroscopy, X‐ray fluorescence spectroscopy, and X‐ray powder diffraction. The results showed good reproducibility.