transition occurred at 690 cI5) which is different from the results of 685cl9 and 700C [19, 20) 0.16 400800 400 012001600 Time(min) Time(min Fig. 3 The in-situ HT p-T curves for SG-YBCO sample after the two sintering cycle. The sample tested in the whole process(a) for the resistivity -testing time p-t curve,(b) for the temperature testing time In order to confirm that the small peak of hT p-T curve appearing at 437C in the cooling process of the second sintering cycle, the p-t and T-t curves of the SG-YBCO samples are measured in the whole process, as shown in fig 3. The structures repeat themselves very well. The small peaks in the p-t curve or p-T curve are not different from the second sintering process. All the 3 characteristic temperatures of the SG-YBCO sample are lower than those of the A-YBCO sample. This could be ascribed to the smaller grain sizes of the SG-YBCO samples. We will discuss it in more detail later 6750 Second sintering First sintering Fig 4 The x-ray patterns of sol gel YBCO sample before sintered and sintered purity p SInt Figure 4 shows the XRd patterns obtained after the SG-YBCO sample finishes the two cring cycles. There are not any diffraction peaks of the YBa2 CusO can be seen in the XRD6 transition occurred at 690℃[5], which is different from the results of 685℃[9], and 700℃. [19,20] (a) (b) Fig. 3 The in-situ HT ρ-T curves for SG-YBCO sample after the two sintering cycle. The sample tested in the whole process (a) for the resistivity – testing time ρ-t curve; (b) for the temperature – testing time T-tcurve. In order to confirm that the small peak of HTρ-T curve appearing at 437℃ in the cooling process of the second sintering cycle, the ρ–t and T–t curves of the SG-YBCO samples are measured in the whole process, as shown in fig.3. The structures repeat themselves very well. The small peaks in theρ–t curve orρ–T curve are not different from the second sintering process. All the 3 characteristic temperatures of the SG-YBCO sample are lower than those of the A-YBCO sample. This could be ascribed to the smaller grain sizes of the SG-YBCO samples. We will discuss it in more detail later. Fig.4 The x-ray patterns of sol gel YBCO sample before sintered and sintered for the first and second cycle. “*” Impurity phase. Figure 4 shows the XRD patterns obtained after the SG-YBCO sample finishes the two sintering cycles. There are not any diffraction peaks of the YBa2Cu3Oy can be seen in the XRD 0 2250 4500 6750 9000 10 20 30 40 50 60 Intensity (a.u.) Cu Kα 2θ/deg. First sintering Second sintering Sol Gel powder (0,0,2) (0,0,3) (0,0,6) (0,0,5) (0,1,3) (1,0,3) (0,0,4) (0,0,7) (1,1,3) (2,0,0) (1,2,3) (2,1,3) (1,1,5) * * (1,1,0) 0 200 400 600 800 1000 0 400 800 1200 1600 Temperature ( ) ℃ Time (min.) 0 0.04 0.08 0.12 0.16 0 400 800 1200 1600 ρ (Ω·cm) Time (min.) 0.08 0.09 0.1 110 120 130 140 ρ (Ω·cm) Time (min.) 0.024 0.026 0.028 0.03 940 950 960 970 ρ (Ω·cm) Time (min.)