Oxygen stoichiometry and superconductivity in (YLa)(Ba<sub>3.4</sub>La<sub>0.6</sub>)Cu<sub>6</sub>O<sub>14+or-y</sub>
J R Grasmeder; M T Weller; D H Gregory; P C Lanchester; B Jayaram; J R Grasmeder; Dept. of Chem., Southampton Univ., UK; M T Weller; Dept. of Chem., Southampton Univ., UK; D H Gregory; Dept. of Chem., Southampton Univ., UK; P C Lanchester; Dept. of Chem., Southampton Univ., UK; B Jayaram; Dept. of Chem., Southampton Univ., UK
Журнал:
Superconductor Science and Technology
Дата:
1989-08-01
Аннотация:
The results of a study into the annealing behaviour of an oxygen-rich superconductor, YLa<sub>1.6</sub>Ba<sub>3.4</sub>Cu<sub>6</sub>O<sub>14+or-y</sub>(-0.12<y<0.47), are reported. As with YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-d</sub>, the oxygen level increases with decreasing quench temperature (T<sub>q</sub>), and materials are superconducting only for anneals below 500 degrees C. However, an unusual behaviour of the unit cell symmetry has been observed by powder X-ray diffraction: orthorhombicity increases with increasing T<sub>q</sub>, and the superconducting materials in this series are tetragonal.
390.1Кб