Title :
The relation between the Mg concentration threshold effect and the defect structures of the congruent Mg:LiNbO3
Author :
Zhang, Qi-ren ; Feng, Xi-Qi
Author_Institution :
Dept. of Phys., Suzhou Railway Teacher´´s Coll., China
fDate :
30 Aug-2 Sep 1992
Abstract :
Congruent Mg:LiNbO3 with Mg concentration of 0, 1.0, 2.7, 5.0, and 6.0 mo 1% has been prepared. A set of defect models consistent with density measurement is proposed. When the Mg concentration (Mg) exceeds a critical value (Mg)c, Nb-site Mg in the form of MgLiMgNb(1/3/)Nbsub Nb(2/3)/O3 appears in the crystal. The (Mg)c varies as the Li/Nb ratio of the crystal and should be 5.30 mo 1% for the congruent crystal. It is suggested that the optical absorption by the reduced crystals is due to defects comprising both F centers, formed under reduction, and different types of dipolarons. When (Mg) exceeds (Mg)c, (Mg Li-MgNb)-F-(MgLi-NbN) occurs in the reduced crystal, which causes an abrupt change in the optical absorption of the crystal
Keywords :
F-centres; impurity and defect absorption spectra of inorganic solids; lithium compounds; magnesium; F centers; Mg concentration threshold effect; congruent LiNbO3:Mg; defect models; defect structures; density measurement; dipolarons; optical absorption; reduced crystals; Bonding; Chemistry; Crystallography; Crystals; Density measurement; Electron traps; Equations; Impurities; Lattices; Niobium;
Conference_Titel :
Applications of Ferroelectrics, 1992. ISAF '92., Proceedings of the Eighth IEEE International Symposium on
Conference_Location :
Greenville, SC
Print_ISBN :
0-7803-0465-9
DOI :
10.1109/ISAF.1992.300617
