The Nature of Surface Oxides on Magnesium Diboride

2001 ◽  
Vol 689 ◽  
Author(s):  
Chandana Meegoda ◽  
Yu. Paderno ◽  
Michael Trenary

ABSTRACTSurface oxides present on polycrystalline MgB2 were characterized by high-resolution x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). X-ray diffraction (XRD) measurements were used to determine the MgB2 phases. XRD line broadening analysis reveals a grain size of 40 nm. XPS results show that MgO and B2O3 are the major surface oxides. Auger spectra provide further evidence of the presence of MgO. The B 1s and Mg 2p peaks have been used to quantify the amount of the surface oxides.

1988 ◽  
Vol 144 ◽  
Author(s):  
Larry P. Sadwick ◽  
Kang L. Wang ◽  
David K. Shuh ◽  
Young K. Kim ◽  
R. Stanley Williams

ABSTRACTThe first epitaxial platinum gallium two (PtGa2) films have been grown on gallium arsenide (GaAs) (100) by co-evaporation of the elements under ultra-high vacuum conditions. An electron beam evaporator and a Knudsen cell were used to produce the platinum and gallium beams, respectively. The resulting films and bulk PtGa2 have been characterized by x-ray diffraction, Auger electron spectroscopy, and x-ray photoelectron spectroscopy. The data confirm the PtGa2 stoichiometry and crystal structure of the films, and demonstrate their chemical stability on GaAs (100). This study supports the contention that PtGa2 can be a suitable, temperature stable contact material on GaAs substrates.


1991 ◽  
Vol 249 ◽  
Author(s):  
Youming Xiao ◽  
Beng Jit Tan ◽  
Steven L. Suib ◽  
Francis S. Galasso

ABSTRACTCoating of SiC (BP-SIGMA) fibers with alumina by a sol-gel process did not cause degradation even after heating to 1000°C in air for 24 h. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Auger electron spectroscopy (AES) and scanning electron microscopy (SEM ) methods were used to study the coating fiber interface.


1997 ◽  
Vol 482 ◽  
Author(s):  
Yu. V. Melnik ◽  
A. E. Nikolaev ◽  
S. I. Stepanov ◽  
A. S. Zubrilov ◽  
I. P. Nikitina ◽  
...  

AbstractGaN, AIN and AIGaN layers were grown by hydride vapor phase epitaxy. 6H-SiC wafers were used as substrates. Properties of AIN/GaN and AIGaN/GaN structures were investigated. AIGaN growth rate was about 1 μm/min. The thickness of the AIGaN layers ranged from 0.5 to 5 μm. The AIN concentration in AIGaN layers was varied from 9 to 67 mol. %. Samples were characterised by electron beam micro analysis, Auger electron spectroscopy, X-ray diffraction and cathodoluminescence.Electrical measurements performed on AIGaN/GaN/SiC samples indicated that undoped AIGaN layers are conducting at least up to 50 mol. % of AIN.


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