On the enlargement of the lattice parameter c in sputter deposited in situ prepared thin films of YBa2Cu3Ox

Growth and branching of CuO nanowires by thermal oxidation of copper

“…4a) indicating that VLS mechanism is not applicable here. Regarding possibility of VS mechanism, it may be noted that CuO is the stable phase upto temperatures of $1100 1C at atmospheric pressure [31]. Vapor pressure of Cu and CuO at temperatures upto 800 1C is very small and Cu 2 O sublimes with vapor pressure of 10 À4 Torr at 600 1C.…”

Secondary Phases in (001)RBa2Cu3O7-δ Epitaxial Thin Films

“…[23][24][25] Too high deposition temperatures and/or too low deposition p(O 2 ) values may also be the reason for R/Ba cation disorder as well as related crystallographic vacancies, mainly in the apical oxygen site. 25,26 In this case, p(O 2 )-T deposition conditions approach the instability border of RBa 2 Cu 3 O 7-δ , or even lie outside the area of thermodynamic stability. 25,26 Apart from point defects and substitution, off-stoichiometry cations may also be incorporated into the film structure due to the formation of extended defects, 27 such as Y 2 Ba 4 Cu 7 O 15-δ or YBa 2 Cu 4 O 8 structural fragments, 28 anti-phase boundaries, and stacking faults.…”

“…25,26 In this case, p(O 2 )-T deposition conditions approach the instability border of RBa 2 Cu 3 O 7-δ , or even lie outside the area of thermodynamic stability. 25,26 Apart from point defects and substitution, off-stoichiometry cations may also be incorporated into the film structure due to the formation of extended defects, 27 such as Y 2 Ba 4 Cu 7 O 15-δ or YBa 2 Cu 4 O 8 structural fragments, 28 anti-phase boundaries, and stacking faults. [28][29][30] The optimal p(O 2 )-T growth conditions, with respect to the films' structural quality and superconducting properties, have often been reported to be located near the equilibrium line between CuO and Cu 2 O oxides.…”

“…Off-stoichiometry components can be incorporated into the structure of growing RBa 2 Cu 3 O 7 - δ films as structural defects, provided the kinetics of the phase formation is slow in comparison with the deposition rate . For example, the formation of cubic perovskite (Y,Ba)CuO 3 - x with a significant cation disorder in the Y and Ba crystallographic positions and/or Y for Ba substitution was observed by XRD, if the film growth was carried out at reduced deposition temperatures. − Too high deposition temperatures and/or too low deposition p (O 2 ) values may also be the reason for R/Ba cation disorder as well as related crystallographic vacancies, mainly in the apical oxygen site. , In this case, p (O 2 )− T deposition conditions approach the instability border of RBa 2 Cu 3 O 7 - δ , or even lie outside the area of thermodynamic stability. , Apart from point defects and substitution, off-stoichiometry cations may also be incorporated into the film structure due to the formation of extended defects, such as Y 2 Ba 4 Cu 7 O 15 - δ or YBa 2 Cu 4 O 8 structural fragments, anti-phase boundaries, and stacking faults. − The optimal p (O 2 )− T growth conditions, with respect to the films' structural quality and superconducting properties, have often been reported to be located near the equilibrium line between CuO and Cu 2 O oxides. , …”

Doping and characterization of YBa2Cu3O7-δthin films prepared by pulsed laser deposition

“…The mobility of oxygen at the O(1) chain sites is several orders of magnitude higher than the mobility of the oxygen at other sites [11]. Hence, providing the temperature is not too high, the occupancy of the other sites can be regarded as fixed, and we can consider the occupancy of the O(1) chain sites alone.…”