High-quality reproducible PLD Y–Ba–Cu–O:Ag thin films up to 4 inch diameter for microwave applications

Morphology and transport properties of Ca-doped superconducting epitaxial YBCO films

“…Percolation and rf residual losses of figures 1-5 fitted by equation (3.1) for ωτ 1 because of j cJ R bn ≈ 1 mV yield R bn and j cJ values summarized in table 1. Whereas the 0% Ca PLD films agree well in R bn and j cJ with similar films [Halbr95,Lorenz02], a target with 10% yields effectively 14% Ca in the film and degraded R bn and j cJ values as deduced from percolation analysis and R res (T ) fits. The R bn decrease with x is proportional to the dρ/dT ∝ 1/n m decrease on Ca doping, seemingly contradicting the j cJ decreases with x obvious in table 1.…”

“…Despite the simple deposition principle of PLD several parameters need to be carefully controlled which otherwise may affect the quality of the deposited films. For example, accurate control of the laser pulse energy and of the substrate temperature, homogeneous target ablation and keeping the laser entrance window clean are extremely important for a high film quality [Lorenz02]. The double-sided films are subsequently deposited at substrate temperature around 760 • C. Because of the radiative heater principle used, the optical absorption properties of the growing film have a large influence on the process control.…”

“…The quality of PLD YBCO films on CeO 2 /Al 2 O 3 for rf applications is well established [Lorenz02], growing best for a composition of about Y 1.1 Ba 1.9 Cu 3 O 7−δ with a percolation network with p ≈ 2 and R bn ≈ 1 n cm 2 ; see, e.g.,…”

Microwave Properties and Critical Current Density of YBCO Thin Films Deposited on CeO2-Buffered Sapphire Substrates Using Sputtering Targets of Different Compositions

“…Achievement of these low R s values is attributed to the formation of the crack-free thick films with a smooth surface. The R s value of Ag-doped YBCO/CeO 2 /sapphire films purchased from Leipzig University 13) was also measured to compare the properties. These films were deposited by PLD on both sides of 2 00 -large and 0.5-mm-thick sapphire hRi substrates.…”

Oxide Thin Film Heterostructures on Large Area, with Flexible Doping, Low Dislocation Density, and Abrupt Interfaces: Grown by Pulsed Laser Deposition

“…In particular, the large-area substrate heater as shown in Figure 2 is the result of a series of prototype heaters with different designs of the heater element and the substrate Laser Chemistry YBCO wafer with two YBCO films at both wafer sides, demonstrating the very good homogeneity of j c using the " j c -scan Leipzig." As much as 15 consecutively deposited 71 × 75 mm 2 YBCO wafers showed such excellent j c -homogeneity, indicating a high reproducibility of the "space qualified" large-area PLD process [9][10][11]. rotation.…”