YBaCuO superconducting films with T<sub>c</sub>=90 K grown off-1:2:3 composition in low oxygen pressure
V Matijasevic; R H Hammond; P Rosenthal; K Shinohara; A F Marshall; M R Beasley; V Matijasevic; Dept. of Appl. Phys., Stanford Univ., CA, USA; R H Hammond; Dept. of Appl. Phys., Stanford Univ., CA, USA; P Rosenthal; Dept. of Appl. Phys., Stanford Univ., CA, USA; K Shinohara; Dept. of Appl. Phys., Stanford Univ., CA, USA; A F Marshall; Dept. of Appl. Phys., Stanford Univ., CA, USA; M R Beasley; Dept. of Appl. Phys., Stanford Univ., CA, USA
Журнал:
Superconductor Science and Technology
Дата:
1991-01-01
Аннотация:
YBaCuO films were grown in-situ by reactive coevaporation at low oxygen pressures. Films made at lower pressures (1-10 mTorr) and in non-equilibrium conditions have a c-axis lattice constant (c<sub>O</sub>) which is expanded compared to the films made at higher pressures (>100 mTorr). The authors have also found that at lower oxygen pressure off-1:2:3-composition and Ba-deficient films have higher T<sub>c</sub>'s (88-90 K) and lower c<sub>O</sub> than do films on-1:2:3 stoichiometry. They suggest that metal-atom point-like defects are quenched into the films at lower oxygen growth pressures.
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