Transport properties of MgB2 films grown on Hastelloy tape: Substrate temperature effect

• Published in: Journal of the Korean Physical Society 2013, 62(2), , pp.284-287
• Main Authors: Kim, Dong-Ho, Park, Young-Soon, Hwang, Tae-Jong, Ranot, Mahipal, Kang, Won-Nam, Chung, Kook-Chae
• Format: Article
• Language: English
• Subjects: Mathematical and Computational Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Theoretical; 물리학
• ISSN: 0374-4884; 1976-8524
• DOI: 10.3938/jkps.62.284

We report on the transport properties of MgB 2 films that were directly grown on Hastelloy tapes by using a hybrid physical chemical deposition method. The substrate temperatures was varied from 480 °C to 540 °C in 20 °C increment while the deposition time and the gas mixing ratio were kept constant at 10 min and H 2 :B 2 H 6 = 70:30, respectively. Within this window of substrate temperature, all the samples except the one grown at 480 °C exhibited critical current densities, J c , much higher than those observed in MgB 2 wires and tapes that were made by using the powder method. For instance, the film grown at 500 °C exhibited a value of J c exceeding 3 × 10 5 A/cm 2 at 4 T and 5 K measured in magnetic fields applied perpendicular to the substrate. In the samples grown at temperatures above 500 °C, a resistance dip was observed in the same field orientation, which can be regarded as evidence for strong flux pinning.