Growth of Laser Ablated YBa_{2}Cu_{3}O_{7} Thin Films Epitaxied on (100)MgO: Influence of In-Plane Misorientations on Low and High Frequency Properties

• Authors: A. Perrin , M. Guilloux-Viry , X. Castel
• Languages of publication: EN

Abstracts

EN

The graphoepitaxial growth of c-axis YBa_{2}Cu_{3}O_{7} laser ablated thin films on (100)MgO induces a competition between two main in-plane orientations due to the large lattice mismatch: ⟨100⟩ YBa_{2}Cu_{3}O_{7} ∥ ⟨100⟩ MgO, c_{⊥ 0} notation or ⟨110⟩ YBa_{2}Cu_{3}O_{7} ∥ ⟨100⟩ MgO, c_{⊥ 45} notation. The ratio of c_{⊥ 45}/c_{⊥ 0} in-plane orientations (η), measured by X-ray diffraction φ scans, is ranging from 0.2% to 49.7% for the films reported here. Their crystalline qualities were compared on the basis of rocking curves (Δθ), electron channeling patterns and reflection high energy electron diffraction diagrams. The coexistence of c_{⊥ 0} and c_{⊥ 45} domains creates high angle grain boundaries. No degradation of T_{c}, residual resistance ratio (RRR) or ΔT_{c} is observed when η increases. In contrast, a strong correlation between microwave losses characterized by surface resistance (R_{S} at 10 GHz and 77 K), inductive losses S(χ") (surface of the χ" peak obtained in a.c. susceptibility at 119 Hz) and η was clearly evidenced. A minimum of losses was found for η between 3 and 6% suggesting the necessity of a low quantity of high angle grain boundaries for films optimization. Finally, some specific processes carried out recently in order to try to efficiently control η, then R_{S} are discussed.

Keywords

EN

73.25.+i; 81.15.-z; 68.55.Jk

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 1997
• Volume: 92
• Issue: 1
• Pages: 115-125

Dates

published

1997-07

Contributors

author

A. Perrin

• Laboratoire de Chimie du Solide et Inorganique Moléculaire, URA CNRS 1495, Université de Rennes I, Avenue du Général Leclerc, 35042 Rennes-Cedex, France

author

M. Guilloux-Viry

• Laboratoire de Chimie du Solide et Inorganique Moléculaire, URA CNRS 1495, Université de Rennes I, Avenue du Général Leclerc, 35042 Rennes-Cedex, France

author

X. Castel

• Laboratoire de Chimie du Solide et Inorganique Moléculaire, URA CNRS 1495, Université de Rennes I, Avenue du Général Leclerc, 35042 Rennes-Cedex, France