tailieunhanh - Effect of Substrate Temperature on the Critical Current Density in the YBa2Cu3O7-x Superconducting Films

A comparative study of effect of substrate temperature (Ts) on the critical current density (Jc) in YBa2Cu3O7-x (YBCO) superconducting films is reported. YBCO superconducting films were fabricated by using the pulsed laser deposition (PLD) technique. The substrate temperature was ranged from 720 to 800 oC in order to find its optimum value for depositing YBCO films. | VNU Journal of Science: Mathematics – Physics, Vol. 32, No. 2 (2016) 8-14 Effect of Substrate Temperature on the Critical Current Density in the YBa2Cu3O7-x Superconducting Films Tran Hai Duc1,*, Duong Thi Thanh Nhan1, Nguyen Huy Sinh1,2 1 Faculty of Physics, VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam 2 Faculty of Physics, Hung Yen University of Technology and Education Received 24 March 2016 Revised 15 May 2016; Accepted 18 June 2016 Abstract: A comparative study of effect of substrate temperature (Ts) on the critical current density (Jc) in YBa2Cu3O7-x (YBCO) superconducting films is reported. YBCO superconducting films were fabricated by using the pulsed laser deposition (PLD) technique. The substrate temperature was ranged from 720 to 800 oC in order to find its optimum value for depositing YBCO films. Results of structural measurements the YBCO films showed that the lattice parameter c were depended on the substrate temperature. The largest value of lattice parameter c calculated from Xray diffraction patterns was obtained for the YBCO film deposited at 780 oC. More interestingly, the critical current density of the YBCO films measured at 65 K also depended on the substrate temperature. The highest value of critical current density of ~ MA/cm2 was also found at the YBCO film deposited at 780 oC. Consequently, the optimum value of Ts of 780 o C might be concluded. Keywords: YBCO, thin film, Jc. 1. Introduction∗ Significant efforts have been carried out on fabricating the second-generation high temperature superconductors (HTS), among them the YBa2Cu3O7- δ (YBCO) is the first HTS showing superconducting state at liquid nitrogen temperature (77 K) [1]. The main purpose has been aimed to utilize the magnetic properties of YBCO at 77 K, those are highly demanded for power applications such as electric transmission lines, motors, generators Fabrications of HTS tapes or films have been done by using a wide variety of deposition .