Study of defects

Catlow C R A1994. Molecular Dynamics Studies of Defects in Solids. In NATO ASI Series C 418 (Defects and Disorder in Crystalline and Amorphous Solids), pp. 357-373. 

Analysis of stress distributions in epitaxial layers In-situ characterization of dislocation motion in semiconductors Depth-resolved studies of defects in ion-implanted samples and of interface states in heterojunctions. 

Vincent, J. C., Barel, M., Challot, F., Contribution to the study of defective green coffee beans, Coll. Int. Chim. Cafes, 7, 133, 1975. (CA86 3698v)... 

James W. Corbett, Institute for the Study of Defects in Solids, Department of Physics, The University at Albany, 1400 Washington Avenue, Albany, New York 12222 (49)... 

INSTITUTE FOR THE STUDY OF DEFECTS IN SOLIDS, PHYSICS DEPARTMENT THE UNIVERSITY AT ALBANY, ALBANY, NEW YORK... 

The description theoretical study of defects frequently refers to some computation of defect electronic structure i.e., a solution of the Schrodin-ger equation (Pantelides, 1978 Bachelet, 1986). The goal of such calculations is normally to complement or guide the corresponding experimental study so that the defect is either properly identified or otherwise better understood. Frequently, the experimental study suffices to identify the basic structure of the defect this is particularly true when the system is EPR (electron paramagnetic resonance) active. However, if the computational method properly simulates the defect, we are provided with a wealth of additional information that can be used to reveal some of the more basic and general features of many-electron defect systems and defect reactions. 

Recent calculations of hyperfine parameters using pseudopotential-density-functional theory, when combined with the ability to generate accurate total-energy surfaces, establish this technique as a powerful tool for the study of defects in semiconductors. One area in which theory is not yet able to make accurate predictions is for positions of defect levels in the band structure. Methods that go beyond the one-particle description are available but presently too computationally demanding. Increasing computer power and/or the development of simplified schemes will hopefully... 

P. A. Thrower, Study of defects in graphite by transmission electron microscopy, Chem. Phys. Carbon, vol. 5, pp. 217-319,1969. 

T. Suski and P. Perlin. High Pressure Studies of Defects and Impurities in Gallium Nitride... 

This section contains a review of results on the extensive study of defect states in the mobility gap of amorphous As- and Sb-containing chalcogenide semiconductors by relaxation technique. For extracting typical features, elemental selenium and simple compositions with relatively low content of arsenic and antimony are exemplified as possible. We will try to attribute TSDC peaks to charge carriers released from the respective trapping levels in the band gap of these materials. 

Wang, J. K Tsai, C. S., and Lee, C. C. (1980). Spectroscopic study of defects in thick specimen using transmission scanning acoustic microscopy. In Scanned image microscopy (ed. E. A. Ash), pp. 137-47. Academic Press, London. [110]... 

McDermott PP.Phakey, An X-Ray Topographic Study of Defect Structures in Cydo-trimethylene Trinitramine , PhysicaStatus-Solids Appl Res, Vol 8, 505-11 (1971) 16) J.E. Abel... 

Improvements in current, established technologies and the introduction of new ways to test materials, nondestmctively are expected to continue apac. One promising method is positron annihilation. The positron is the antiparticle of the electron thus apositron/electron pair is unstable and will annihilate. In this process, two gamma rays at approximately 180 to one another are emitted from the center of the mass of the pair. A very slight departure from 180° is directly proportional to the transverse component of the momentum, of the pair. The momenta of the electrons involved in such collisions can be calculated from the geometry and intensity of the gamma rays. The dynamics of the clcctron/positron system underlie the use of the technique for the study of defects in materials,... 

This section has provided a very brief introduction to some of the most common surface defects in silicon. However the study of defects in silicon is a rich and intensely studied field not least due to its importance for the functionality of devices, and a more comprehensive review can be found in [23]. 

Further examples of positron study of defects in HTSC are studies carried out to understand the nature of flux-pinning defects that lead to an increase in critical-current density on neutron-irradiated Y 1 2 3. Experiments [59] on positron lifetime and critical-current density measurements on various neutron-irradiated samples of Y 1 2 3 indicate that the critical current density is correlated with the micro-void density, as obtained from the analysis of positron lifetime measurements. Investigation of defects in other HTSC superconductors, such as La-Sr-Ca-Cu-0 [60], Bi-Sr-Ca-Cu-0 [49], and Nd-Ce-Cu-O [52], have also been carried out. 

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