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Deposition and characterization of sputtered hexaboride coatings; Abscheidung und Charakterisierung aufgestaeubter Hexaboridschichten

Abstract

Hexaborides of the rare-earth elements ReB{sub 6} are potential materials for cathode applications since they combine properties such as low work function, good electrical conductivity, high melting point as well as low volatility at high temperatures. Due to their high hardness and colorations ranging from blue to purple these compounds are also considered for applications to coatings for decoration of consumer products. At present, either rods of sintered LaB{sub 6} or single LaB{sub 6} crystals are indirectly heated to induce emission. In this workboride coatings were deposited onto various substrates employing non-reactive magnetron sputtering from LaB{sub 6}, CeB{sub 6}, SmB{sub 6} and YB{sub 6} targets. Coatings deposited were examined using scanning electron microscopy, X-ray diffraction, electron probe microanalysis. Vickers microhardness, colorimeter and spectroscopic ellipsometry measurements. Electron emission characteristics of the coatings were studied by the thermionic emission and the contact potential method. After optimization of the sputtering parameters fine-columnar or partially amorphous films with atomic ratios of boron to metal in the order of 5 to 7.5 were obtained. The tendency to form the corresponding hexaboride phase decreases from LaB{sub 6}, CeB{sub 6} and SmB{sub 6} to YB{sub 6}. The work function was measured to be in the range of  More>>
Authors:
Publication Date:
Jun 01, 1996
Product Type:
Thesis/Dissertation
Reference Number:
EDB-00:027223
Resource Relation:
Other Information: TH: Thesis (Dr. mont.); PBD: Jun 1996
Subject:
36 MATERIALS SCIENCE; CERIUM BORIDES; COATINGS; LANTHANUM BORIDES; OPTICAL PROPERTIES; SCANNING ELECTRON MICROSCOPY; SPUTTERING; THERMIONICS; YTTRIUM BORIDES
OSTI ID:
20030807
Research Organizations:
Montanuniversitaet Leoben, 8700 Leoben (Austria)
Country of Origin:
Austria
Language:
German
Other Identifying Numbers:
TRN: AT9900433000121
Availability:
Available from Montanuniversitaet Leoben Bibliothek, 8700 Leoben, Franz-Josef-Strasse 18 (AT)
Submitting Site:
INIS
Size:
201 pages
Announcement Date:
Jun 05, 2000

Citation Formats

Waldhauser, W. Deposition and characterization of sputtered hexaboride coatings; Abscheidung und Charakterisierung aufgestaeubter Hexaboridschichten. Austria: N. p., 1996. Web.
Waldhauser, W. Deposition and characterization of sputtered hexaboride coatings; Abscheidung und Charakterisierung aufgestaeubter Hexaboridschichten. Austria.
Waldhauser, W. 1996. "Deposition and characterization of sputtered hexaboride coatings; Abscheidung und Charakterisierung aufgestaeubter Hexaboridschichten." Austria.
@misc{etde_20030807,
title = {Deposition and characterization of sputtered hexaboride coatings; Abscheidung und Charakterisierung aufgestaeubter Hexaboridschichten}
author = {Waldhauser, W}
abstractNote = {Hexaborides of the rare-earth elements ReB{sub 6} are potential materials for cathode applications since they combine properties such as low work function, good electrical conductivity, high melting point as well as low volatility at high temperatures. Due to their high hardness and colorations ranging from blue to purple these compounds are also considered for applications to coatings for decoration of consumer products. At present, either rods of sintered LaB{sub 6} or single LaB{sub 6} crystals are indirectly heated to induce emission. In this workboride coatings were deposited onto various substrates employing non-reactive magnetron sputtering from LaB{sub 6}, CeB{sub 6}, SmB{sub 6} and YB{sub 6} targets. Coatings deposited were examined using scanning electron microscopy, X-ray diffraction, electron probe microanalysis. Vickers microhardness, colorimeter and spectroscopic ellipsometry measurements. Electron emission characteristics of the coatings were studied by the thermionic emission and the contact potential method. After optimization of the sputtering parameters fine-columnar or partially amorphous films with atomic ratios of boron to metal in the order of 5 to 7.5 were obtained. The tendency to form the corresponding hexaboride phase decreases from LaB{sub 6}, CeB{sub 6} and SmB{sub 6} to YB{sub 6}. The work function was measured to be in the range of 2.6 to 3.3 eV. Vickers microhardness values lie between 1500 and 2000 HVO.01. LaB{sub 6} coatings showed the most pronounced visual color impression corresponding to dark violet. The results obtained indicate that sputtered hexaboride films are well suited for decorative and thermionic applications. (author)}
place = {Austria}
year = {1996}
month = {Jun}
}