A1 Refereed original research article in a scientific journal
Effect of post-annealing on thin YBCO films deposited from a nanocrystalline target
Authors: Huhtinen H, Lahderanta E, Paturi P
Publisher: KLUWER ACADEMIC/PLENUM PUBL
Publication year: 1999
Journal:: Journal of Low Temperature Physics
Journal name in source: JOURNAL OF LOW TEMPERATURE PHYSICS
Journal acronym: J LOW TEMP PHYS
Volume: 117
Issue: 3-4
First page : 795
Last page: 799
Number of pages: 5
ISSN: 0022-2291
DOI: https://doi.org/10.1023/A:1022517916782
Abstract
Pulsed laser deposition is used to ablate thin superconducting YBCO films on SrTiO3 substrates. The most important parameters of thin superconducting films are high critical current density, ability to stand magnetic fields and smoothness of surfaces. Smoothness is important in fabrication of layered structures and for research of basic properties of thin superconducting structures. The target sintered from YBCO nanopowder is a promising material for making films which meet most of the requirements above. Investigations by AFM show that our target has grains about one order of magnitude smaller than usual grain size of commercial targets. At optimal deposition parameters, the oxygen pressure of 0.4 torr in the chamber and the substrate temperature 725 degrees C, films with T-c = 90 K, J(c) = 8 x 10(6) A/cm(2) (77 K) and RMS surface roughness = 1.5 nm are obtained. Thermal annealing of the deposited films for 18 h at 900 degrees C further increases the value of J(c).
Pulsed laser deposition is used to ablate thin superconducting YBCO films on SrTiO3 substrates. The most important parameters of thin superconducting films are high critical current density, ability to stand magnetic fields and smoothness of surfaces. Smoothness is important in fabrication of layered structures and for research of basic properties of thin superconducting structures. The target sintered from YBCO nanopowder is a promising material for making films which meet most of the requirements above. Investigations by AFM show that our target has grains about one order of magnitude smaller than usual grain size of commercial targets. At optimal deposition parameters, the oxygen pressure of 0.4 torr in the chamber and the substrate temperature 725 degrees C, films with T-c = 90 K, J(c) = 8 x 10(6) A/cm(2) (77 K) and RMS surface roughness = 1.5 nm are obtained. Thermal annealing of the deposited films for 18 h at 900 degrees C further increases the value of J(c).
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