Development of a model for on-line control of crystal growth by the AHP method

2007 ◽  
Vol 303 (1) ◽  
pp. 180-186 ◽  
Author(s):  
M.A. Gonik ◽  
A.V. Lomokhova ◽  
M.M. Gonik ◽  
A.T. Kuliev ◽  
A.D. Smirnov
Keyword(s):  
2001 ◽  
Author(s):  
V. Golyshev ◽  
M. Marchenko ◽  
E. Leonardi ◽  
A. Deal ◽  
R. Abbaschian ◽  
...  

1999 ◽  
Vol 572 ◽  
Author(s):  
P. J. Wellmann ◽  
M. Bickermann ◽  
M. Grau ◽  
D. Hofmann ◽  
T. L. Straubinger ◽  
...  

ABSTRACTAn advanced method based on x-ray imaging is presented which allows us to visualize the ongoing processes during physical vapor transport (PVT) growth of SiC. Using a high resolution and high speed x-ray imaging detector based on image plates and digital recording we are able to follow the SiC bulk single crystal growth as well as the evolution of the SiC powder source inside the inductively heated graphite crucible on-line and quasi-continuously.


2002 ◽  
Author(s):  
Marina P. Marchenko ◽  
I. V. Frjazinov ◽  
Vladimir D. Golyshev ◽  
Victoria Timchenko ◽  
Eddie Leonardi ◽  
...  

2007 ◽  
Vol 303 (1) ◽  
pp. 193-198 ◽  
Author(s):  
Marina P. Marchenko ◽  
Vladimir D. Golyshev ◽  
Svetlana V. Bykova

Author(s):  
Necip Güven ◽  
Rodney W. Pease

Morphological features of montmorillonite aggregates in a large number of samples suggest that they may be formed by a dendritic crystal growth mechanism (i.e., tree-like growth by branching of a growth front).


Author(s):  
Joanna L. Batstone

Interest in II-VI semiconductors centres around optoelectronic device applications. The wide band gap II-VI semiconductors such as ZnS, ZnSe and ZnTe have been used in lasers and electroluminescent displays yielding room temperature blue luminescence. The narrow gap II-VI semiconductors such as CdTe and HgxCd1-x Te are currently used for infrared detectors, where the band gap can be varied continuously by changing the alloy composition x.Two major sources of precipitation can be identified in II-VI materials; (i) dopant introduction leading to local variations in concentration and subsequent precipitation and (ii) Te precipitation in ZnTe, CdTe and HgCdTe due to native point defects which arise from problems associated with stoichiometry control during crystal growth. Precipitation is observed in both bulk crystal growth and epitaxial growth and is frequently associated with segregation and precipitation at dislocations and grain boundaries. Precipitation has been observed using transmission electron microscopy (TEM) which is sensitive to local strain fields around inclusions.


Author(s):  
M. G. Lagally

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.


Author(s):  
William Krakow

In the past few years on-line digital television frame store devices coupled to computers have been employed to attempt to measure the microscope parameters of defocus and astigmatism. The ultimate goal of such tasks is to fully adjust the operating parameters of the microscope and obtain an optimum image for viewing in terms of its information content. The initial approach to this problem, for high resolution TEM imaging, was to obtain the power spectrum from the Fourier transform of an image, find the contrast transfer function oscillation maxima, and subsequently correct the image. This technique requires a fast computer, a direct memory access device and even an array processor to accomplish these tasks on limited size arrays in a few seconds per image. It is not clear that the power spectrum could be used for more than defocus correction since the correction of astigmatism is a formidable problem of pattern recognition.


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