Epitaxial CeO2 buffer layers for YBa2Cu3O7−δ films on sapphire

Abstract

Epitaxial CeO2 buffer layers and YBa2Cu3O7−δ thin films have been grown in situ on (11̄02) sapphire by electron beam evaporation. Buffer layers of only 20 nm thickness inhibit interdiffusion between YBa2Cu3O7−δ and Al2O3 as determined by depth profiling using x-ray photoelectron spectroscopy. The layers show smooth surfaces and narrow interfaces. High lattice perfection of the CeO2 layer has been shown by x-ray diffraction. Laue oscillations up to ninth order have been observed in thin CeO2 buffer layers on sapphire. We found only one epitaxial orientation with YBa2Cu3O7−δ (001) ∥ CeO2 (001) ∥ Al2O3 (11̄02) and YBa2Cu3O7−δ [110] ∥ CeO2 [100] ∥ Al2O3 [112̄0]. YBa2Cu3O7−δ films grown on these buffer layers reveal Tc=88±0.5 K, ρ(300 K)=380 μΩ cm, and jc(77 K, 0 T)=1.3×106 A/cm2.

Deposition of cerium oxide films on Si (100) and glass substrates using the ESAVD method

“…Physical deposition techniques, such as pulsed laser deposition (PLD) [9,10], magnetron sputtering [17], electron beam evaporation [18], and molecular beam epitaxy (MBE) [19] have been used to produce CeO 2 films. Several chemicalbased preparation methods have also been applied.…”

High-speed epitaxial growth of (100)-oriented CeO2 film on r-cut sapphire by laser chemical vapor deposition

“…3(a)). This was attributed to the {110} planes with the complementary angle of 45°to the (100) plane [12][13][14][15][16][17]. The pole figure of the ð1213Þ reflection of Al 2 O 3 substrate showed a twofold symmetry at α = 64° (Fig.…”

X-ray diffraction measurements and depth profiling by secondary neutral mass spectrometry on epitaxially grown high-Tc superconducting thin films

“…We found perfect azimuthal alignment. In the case of CeO z buffer layer the YBazCu30 v ~ thin films were grown on these buffers under the angle of 45 ~ due to the resulting smaller lattice misfit [8].…”