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Title: Effect of different thickness crystalline SiC buffer layers on the ordering of MgB{sub 2} films probed by extended x-ray absorption fine structure

Extended X-ray absorption fine structure (EXAFS) spectroscopy is a powerful method to investigate the local structure of thin films. Here, we have studied EXAFS of MgB{sub 2} films grown on SiC buffer layers. Crystalline SiC buffer layers with different thickness of 70, 100, and 130 nm were deposited on the Al{sub 2}O{sub 3} (0001) substrates by using a pulsed laser deposition method, and then MgB{sub 2} films were grown on the SiC buffer layer by using a hybrid physical-chemical vapor deposition technique. Transition temperature of MgB{sub 2} film decreased with increasing thickness of SiC buffer layer. However, the T{sub c} dropping went no farther than 100 nm-thick-SiC. This uncommon behavior of transition temperature is likely to be created from electron-phonon interaction in MgB{sub 2} films, which is believed to be related to the ordering of MgB{sub 2} atomic bonds, especially in the ordering of Mg–Mg bonds. Analysis from Mg K-edge EXAFS measurements showed interesting ordering behavior of MgB{sub 2} films. It is noticeable that the ordering of Mg–B bonds is found to decrease monotonically with the increase in SiC thickness of the MgB{sub 2} films, while the opposite happens with the ordering in Mg–Mg bonds. Based on these results, crystalline SiC buffermore » layers in MgB{sub 2} films seemingly have evident effects on the alteration of the local structure of the MgB{sub 2} film.« less
Authors:
; ;  [1] ; ;  [2] ;  [3] ;  [4]
  1. Department of Physics, Chungbuk National University, 361 763 Cheongju (Korea, Republic of)
  2. Department of Physics, Sungkyunkwan University, 440 746 Suwon (Korea, Republic of)
  3. Department of Advanced Physics, Hirosaki University, 036 8561 Aomori (Japan)
  4. Physics Division, School of Science Education, Chungbuk National University, 361 763 Cheongju (Korea, Republic of)
Publication Date:
OSTI Identifier:
22277958
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION SPECTROSCOPY; ALUMINIUM OXIDES; ELECTRON-PHONON COUPLING; ENERGY BEAM DEPOSITION; FINE STRUCTURE; LASER RADIATION; LAYERS; MAGNESIUM BORIDES; PULSED IRRADIATION; SILICON CARBIDES; SUBSTRATES; THIN FILMS; TRANSITION TEMPERATURE; X-RAY SPECTROSCOPY