LiNbO₃:Mg 단결정의 결함구조에 관한 연구 = A Study for the Defect Structure in LiNbO₃:Mg Single Crystals

다국어 초록 (Multilingual Abstract)

Litium niobate(LiNbO₃) is one of the widely used materials in acousto- and optoelectronics. Nevertheless the search for dopants, which intentionally change its properties, is still being continued nowadays.
In this thesis, a congruent LiNbO₃crystal, congruent LiNbO₃crystals with doped Mg and with Mg and codoped with Mn were grown by the Czochralski method. These were investigated by UV-and IR-spectrophotometry. The position of the UV absorption edge and the shape and peak point of the absorption band of the OH vibrational band changed monotonously up to a critical concentration of Mg ions. The mechanism of the incorporation of Mg ions changes at this concentration.
On the basis of these results, the intrinsic and the extrinsic defect structure models in LiNbO₃crystals were examined. The behaviour of v(OH) reflects the defect structure and supports the Li-site vacancy model as the intrinsic defect structure model and the corresponding extrinsic defect model. A brief discussion is also given of the behaviour of v(OH) in LiNbO₃crystals simultaneously doped with several kinds of impurity.