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"Un-annealed and Annealed Pd Ultra-Thin Film on SiC Characterized by Scanning Probe Microscopy and X-ray Photoelectron Spectroscopy"Pd/SiC has been used as a hydrogen and a hydrocarbon gas sensor operated at high temperature. UHV (Ultra High Vacuum)-Scanning Tunneling Microscopy (STM), Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS) techniques were applied to study the relationship between the morphology and chemical compositions for Pd ultra-thin films on SiC (less than 30 angstroms) at different annealing temperatures. Pd ultra-thin film on 6H-SiC was prepared by the RF sputtering method. The morphology from UHV-STM and AFM shows that the Pd thin film was well deposited on SiC substrate, and the Pd was partially aggregated to round shaped participates at an annealing temperature of 300 C. At 400 C, the amount of surface participates decreases, and some strap shape participates appear. From XPS, Pd2Si was formed on the surface after annealing at 300 C, and all Pd reacted with SiC to form Pd2Si after annealing at 400 C. The intensity of the XPS Pd peak decreases enormously at 400 C. The Pd film diffused into SiC, and the Schottky barrier height has almost no changes. The work shows the Pd sicilides/SiC have the same electronic properties with Pd/SiC, and explains why the Pd/SiC sensor still responds to hydrogen at high operating temperatures.
Document ID
20000032287
Acquisition Source
Headquarters
Document Type
Conference Paper
Authors
Lu, W. J.
(Fisk Univ. Nashville,TN United States)
Shi, D. T.
(Fisk Univ. Nashville,TN United States)
Elshot, K.
(Fisk Univ. Nashville,TN United States)
Bryant, E.
(Fisk Univ. Nashville,TN United States)
Lafate, K.
(Fisk Univ. Nashville,TN United States)
Chen, H.
(Fisk Univ. Nashville,TN United States)
Burger, A.
(Fisk Univ. Nashville,TN United States)
Collins, W. E.
(Fisk Univ. Nashville,TN United States)
Date Acquired
August 19, 2013
Publication Date
February 22, 1998
Publication Information
Publication: NASA University Research Centers Technical Advances in Aeronautics, Space Sciences and Technology, Earth Systems Sciences, Global Hydrology, and Education
Volume: 2 and 3
Subject Category
Nonmetallic Materials
Report/Patent Number
98URC042
Funding Number(s)
CONTRACT_GRANT: NAG3-1430
CONTRACT_GRANT: NAG3-2012
CONTRACT_GRANT: NAGW-2925
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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