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MgB 2 thick film with T C = 40.2 K deposited on sapphire substrate
Author(s) -
Zhang Kaicheng,
Ding Lili,
Zhuang Chenggang,
Chen Liping,
Chen Chinping,
Feng Qingrong
Publication year - 2006
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200522262
Subject(s) - sapphire , materials science , residual resistivity , superconductivity , chemical vapor deposition , substrate (aquarium) , hysteresis , electrical resistivity and conductivity , scanning electron microscope , fabrication , extrapolation , transition temperature , condensed matter physics , deposition (geology) , critical field , analytical chemistry (journal) , nanotechnology , composite material , optics , chemistry , alternative medicine , mathematics , mathematical analysis , laser , oceanography , pathology , engineering , biology , paleontology , chromatography , medicine , physics , sediment , electrical engineering , geology
A thick MgB 2 film has been successfully deposited on a (001) crystalline surface of sapphire by the method of hybrid physical–chemical vapor deposition (HPCVD). The film thickness is about 1.3 μm, having a dense and interlaced structure. The film surface, as shown by scanning electron microscopy, is stacked with MgB 2 microcrystals. Transport measurements using the four‐probe technique demonstrate that its critical temperature is about 40.2 K, with a sharp transition width of 0.15 K. The transition is higher by 1 K than those commonly reported at 39 K. The residual resistivity ratio (RRR) is about 11. By extrapolation, H C2 (0) is determined as 13.7 T from magneto‐transport measurements. Also, from hysteresis measurements and applying the Bean model, the critical current density is estimated as 5 × 10 10 A/m 2 in zero magnetic field. The investigation demonstrates that HPCVD is an effective technique to fabricate MgB 2 thick films with decent superconducting properties. Hence, it is important for future superconducting applications, in particular as a crucial preliminary stage in the fabrication of superconducting tape. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)