Interrelation of intrinsic and extrinsic defects – congruent, stoichiometric, and regularly ordered lithium niobate |
| |
Authors: | G Malovichko V Grachev O Schirmer |
| |
Institution: | Fachbereich Physik, Osnabrück Universit?t, Barbarastr. 7, 49069 Osnabrück, Germany (Fax: +49-541/969-26-70; E-mail: gmalovic@mail.rz.uni-osnabrueck.de), DE Institute for Problems of Material Sciences, National Academy of Sciences, Kiev, Ukraine, UA
|
| |
Abstract: | A new approach to the intrinsic and extrinsic defect subsystems, considering them as one integrated functional system, is
developed for complex oxides. The strong interrelation of these subsystems becomes especially apparent when concentrations
of both defect classes are comparable. A new parameter, reflecting the total intrinsic defect concentration, is introduced
to determine the degree of crystal imperfection. The necessity of at least two calibrated samples – congruent and regularly
ordered crystals – is substantiated. The accuracy by which the parameter can be determined can serve as a criterion in comparison
of different methods of crystal characterisation. A procedure for crystal calibration by several physical characteristics
is illustrated. Such a heuristic generalisation of the concept of mutual correlation of the whole defect system and the material
only became possible on the basis of experimental and theoretical study of large numbers of LiNbO3 crystals. The spectra of EPR, NMR, ENDOR, and other properties of crystals with different compositions, diverse modifiers
(K, Mg,...), and various probe impurities have been analysed. It is found that crystals with vanishingly small concentration
of intrinsic defects offer extraordinary informative opportunities. Their micro- and macroscopic properties are discussed.
The developed ideas have a general character; therefore they should also be valid for other non-stoichiometric complex oxides.
Received: 3 December 1998 / Revised version: 15 February 1999 / Published online: 12 April 1999 |
| |
Keywords: | PACS: 76 30 Fc 76 30 Kg 77 84 Dy 76 70 |
本文献已被 SpringerLink 等数据库收录! |
|