We report the growth of (Cu,C)Ba2CuOy thin films by molecular-beam epitaxy (MBE). The c-axis oriented film is obtained with a = 3.959 Å and c = 8.140 Å. The Tc values of the film on an NdGaO3 substrate are Tc(on) ∼ 35 K and Tc(zero) ∼ 18 K. The Tc(on) is increased to 70 K for a 12 nm-thick film deposited on an infinite-layer CaCuO2 buffer layer. This suggests that the layer-by-layer growth method using (Cu,C)Ba2CuOy and [CaCuO2]n-1 is a promising way to obtain higher member (Cu,C)Ba2Can-1CunOy (n ≥ 2) thin films with a higher Tc. We also find that the Ba-Cu-O phase with c ∼ 4.0 Å, which is known as the 'infinite-layer BaCuO2' phase, can be obtained only in a slightly CO2 atmosphere. This means that the phase contains carbon in its structure.
- Thin films
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering