Raman tensor analysis of sapphire single crystal and its application to define crystallographic orientation in polycrystalline alumina

2009 ◽  
Vol 246 (8) ◽  
pp. 1893-1900 ◽  
Author(s):  
Maria Chiara Munisso ◽  
Wenliang Zhu ◽  
Giuseppe Pezzotti
2001 ◽  
Vol 16 (2) ◽  
pp. 333-335 ◽  
Author(s):  
P. Nekvindova ◽  
J. Spirkova-Hradilova ◽  
J. Schröfel ◽  
V. Perina

The possibility of localized doping by Er3+ diffusion at moderate (less than 500 °C) temperature was for the first time demonstrated for sapphire single crystal wafers. The doping was achieved by immersing the substrate wafers into reaction melt containing small amounts of erbium salt. The crucial point of the presented technology was a crystallographic orientation of the used wafers. The most suitable orientation of the cuts was the “X-cut” with orientation (11–20). The strong anisotropy of the moderate temperature Er3+ doping into lithium niobate and sapphire was explained on the basis of the crystal structure of particular cuts.


Rare Metals ◽  
2006 ◽  
Vol 25 (6) ◽  
pp. 260-266 ◽  
Author(s):  
J LI ◽  
X SU ◽  
M NA ◽  
H YANG ◽  
J LI ◽  
...  

Author(s):  
Vladimir Yu. Sadovoy ◽  
Vladimir D. Blank ◽  
Sergey A. Terentiev ◽  
Dmitriy V. Teteruk ◽  
Sergey Yu. Troschiev

Dependence of secondary electron emission coefficient on the chosen crystallographic orientation for a synthetic single crystal diamond of type IIb, grown up by method of a temperature gradient, was investigated. The type IIb of single crystal diamond was chosen because of wide applicability in different areas of microelectronics and the semiconductor properties. Quantitative measurements of secondary electron emission coefficients with energy of primary beam about 7 keV and above for various crystallographic orientations was carried out: the highest coefficient of secondary electronic emission are recorded for the direction (100), cubic sector, and also in intergrowth area that is confirmed by a picture of distribution of the luminescence intensity for various sectors of a single crystal received by means of true secondary electrons detector of scanning electron microscope. The results for (100) area are outstanding: 8.18 at primary beam energy of 7 keV, 10.13 at 10 keV, 49.78 at 30 keV. The results for intergrowth area are similar: 10.10 at primary beam energy of 7 keV, 13.56 at 10 keV, 64.41 at 30 keV. The crystallographic directions (111) have shown secondary electron emission coefficient 4-6 times lower in comparison with (100) and intergrowth area: 2.54 on the average at primary beam energy of 7 keV, 2.75 at 10 keV, 10.03 at 30 keV. The non-standard behavior of secondary electron emission coefficient at the high energy primary beam for all orientations of single crystal diamond is shown: increase in secondary electron emission coefficient with increase in energy of primary beam. At the moment the reason of such behavior is not clear up to the end and since this fact causes a great interest of researchers, considerably expands applicability of the existing devices and detectors due to replacement of a functional element on diamond one, and also opens big opportunities for formation of new field of microelectronics, this facts demand further in-depth study by means of various methods of the structural and surface analysis.


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