Abstract：High-quality epi-MgO buffer layers under different O2/Ar pressure ratios are fabricated by rf magnetron sputtering on textured IBAD-MgO templates. Under the total deposition pressure remaining constant (14 Pa), the effect of changing the ratio of O2/Ar pressure from 1:4 to 3:2 on the microstructure and surface morphology of epi-MgO films is studied. The microstructure and morphology of epi-MgO are fully characterized by x-ray diffraction, atom force microscope and scanning electron microscope. The best texture quality of epi-MgO with an out-plane Δω value of 1.8° and an in-plane Δ? value of 5.22° are obtained under the ratio of O2/Ar pressure 3:2. Further, the surface morphology indicates that the surface of epi-MgO is smooth with rms surface roughness about 4.7 nm at O2/Ar pressure ratio 3:2. After that, GdBa2Cu3O7?δ (GBCO) layers are deposited on the CeO2 cap layer buffered epi-MgO/IBAD-MgO templates to assess the efficiency of such a buffer layer stack. The critical current density of GBCO films (thickness of 200 nm) is higher than 3 MA/cm2, indicating that epi-MgO/IBAD-MgO is promising for depositing superconducting layers with a higher critical current density.
(Effects of crystal defects, doping and substitution)
引用本文:
. [J]. 中国物理快报, 2014, 31(03): 37402-037402.
LUO Qiang, LIU Lin-Fei, XIAO Gui-Na, LI Yi-Jie. Effect of the O2/Ar Pressure Ratio on the Microstructure and Surface Morphology of Epi-MgO/IBAD-MgO Templates for GdBa2Cu3O7?δ Coated Conductors. Chin. Phys. Lett., 2014, 31(03): 37402-037402.
2014, Vol. 31 
