High-quality single-crystal Nb films and influences of substrates on the epitaxial growth

• DOI: 10.1063/1.337323
• Publication Date: 2002-07-26T12:53:33Z
• Authors: Gin-ichiro Oya; Masanori Koishi; Yasuji Sawada
• Keywords: Crystal (programming language)

Highly pure single-crystal Nb films (thickness, ∼2000 Å) with high superconducting transition temperatures Tc of ∼9.3 K and resistance ratios R300/R10 up to ∼200 are successfully grown epitaxially on sapphire (α-Al2O3) MgO substrates at ∼500–∼700 °C by using an electron-beam evaporation technique. The most high-quality film (with the maximum 9.45 199) is obtained a (11̄02) substrate, which has thermal expansion coefficient very close that as well small lattice misfit Nb. quality found be lowered deposition coefficients different far from because production internal strains defects in cooled down.