标题：Study the relation between band gap value and lattice constant of MgTi2O4
作者：Shi, Yujun; Lian, Jie; Hu, Wei; Liu, Yuxiang; He, Ge; Jin, Kui; Song, Haonan; Dai, Kai; Fang, Jiaxiong
作者机构：[Shi, Yujun; Lian, Jie; Liu, Yuxiang; Song, Haonan; Dai, Kai] Shandong Univ, Sch Informat Sci & Engn, Qingdao 266237, Shandong, Peoples R China.; [H 更多
通讯作者地址：[Lian, J]Shandong Univ, Sch Informat Sci & Engn, Qingdao 266237, Shandong, Peoples R China.
来源：JOURNAL OF ALLOYS AND COMPOUNDS
关键词：MgTi2O4; Spectroscopic ellipsometry; Optical constants; Band gap
摘要：As an accurate technique, spectroscopic ellipsometry (SE) is utilized to study the dielectric function (epsilon = epsilon(r) + i epsilon(i)) of spinel oxide MgTi2O4 (MTO) thin films with good orientation. C-axis lattice length and Ti ions valence state are characterized by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. Here, we find that c-axis lattice constants have the positive correlation with band gaps which are obtained by fitting the spectra of d(2)(E-2 epsilon(i))/dE(2) via standard critical points model in MTO, and this phenomenon can be revealed by the Ti ions valence state. Moreover, the band gap value of MTO measured by experiment is consistent with the result of first-principles calculations. (C) 2019 Elsevier B.V. All rights reserved.