During the GdBCO film fabrication, the substrate temperature, O/Ar mixed gas pressure, and

sputtering power are 780°C, 25 Pa, and 80 W, respectively. The O/Ar is 1:1. Seven samples with various thicknesses are fabricated. Film thickness is controlled by different sputtering times, while other parameters are fixed. The thickness for #Selleckchem Vadimezan randurls[1|1|,|CHEM1|]# the studied samples is measured using a step profiler. The seven samples are 5 cm long and 1 cm wide. In order to get an average thickness of our samples, especially for the thicker films with a-axis outgrowths, ten points along the sample width direction are chosen for thickness measurement using the step profiler for every sample. The distance between the chosen points is 0.1 cm. The average thicknesses of our samples are 200, 390, 602, 810, 1,030, 1,450, AZD5582 and 2,100 nm, respectively. The thickness homogeneity along the length direction (not the width direction) is very good for the studied samples. Four films are used to analyze the development of the microstructure and stress of GdBCO films. Their

thicknesses are 200, 1,030 1,450, and 2,100 nm, and they are named F200, F1030, F1450, and F2100, respectively. The microstructure and stress of the films are studied by XRD, SEM, AFM, and XPS analysis. The I c is measured using the standard four-probe method. A voltage criterion of 1 μV/cm is used to determine I c in the I-V curves. Results and discussion Film texture and surface morphology Figure 1 shows the log scale of θ-2θ XRD patterns for the GdBCO films with different ADAMTS5 thicknesses from 200 to 2,100 nm. Except for the peaks from the CeO2/YSZ/CeO2-buffered Ni-W substrate and other three small peaks, all of the peaks can be attributed to GdBCO films. Weak CeO2 (111) and NiO (002) peaks appear at 28° and 41°, respectively. The weak CeO2 (111) peak originates from the buffer layers, while

the NiO (002) peak suggests that there is a minor oxidation of the Ni-W substrate. The (00L) peaks belong to c-axis grains. The (H00) peaks indicate a-axis grains. Double peaks appear in Figure 1 around 2θ = 23° and 46° as the film thickness exceeds 1,030 nm. The reflections at 22.7° and 46.3° are the (003) c-axis orientation and (006) c-axis orientation, respectively. The reflections at 23.3° and 47.5° correspond with the a-axis alignment of (100) and (200). We use the ratio I = I (200) / I (006) + I (200) to evaluate the a-axis grains’ volume fraction of the GdBCO film, as shown in Figure 2. In the 200-nm-thick GdBCO film, no (200) peak is observed, so the corresponding ratio I is 0% for the thinnest film, which indicates that all the grains grow along the c-axis. As the thickness increases to 1,030 and 1,450 nm, the ratio I increases to 3.3% and 10.7%, respectively. This illustrates that a-axis-oriented grains appear in the 1,030-nm-thick GdBCO film, and the a-axis grains’ volume fraction becomes more and more as the thickness comes up to 1,450 nm.