Li + diffusivity in 5 mol% MgO-doped LiNbO 3 crystal and Li-poor vapor transport equilibration effect on its surface composition

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Author(s)

  • Zhen Wang
  • Ping-Rang Hua
  • Shuai Zhang
  • Dao-Yin Yu
  • De-Long Zhang

Related Research Unit(s)

Detail(s)

Original languageEnglish
Pages (from-to)152-156
Journal / PublicationJournal of Alloys and Compounds
Volume530
Publication statusPublished - 25 Jul 2012

Abstract

Diffusivity of Li + in 5 mol% (in growth melt) MgO-doped LiNbO 3 crystal has been studied as a function of Li 2O-content ranging from 43.4 to 44.4 mol% under different temperatures. First, diffusion-limited Li 2O-content depth profiles were produced by carrying out Li-poor vapour transport equilibration (VTE) treatments on two 0.5-mm-thick MgO-doped LiNbO 3 plates at 1100 and 1130 °C for 40 h. Second, the profiles were obtained by alternatively doing the optical polish to one crystal surface and the Li 2O-content characterization on the polished surface through the measurement of birefringence. Third, Boltzmann-Matano method was applied to the profile to derive the Li + diffusivity as a function of Li 2O-content. The results show that the diffusivity decreases with the reduced Li 2O-content by at least two orders of magnitude as the Li 2O-content reduces by 1 mol% from the as-grown state. In the Li 2O-content range studied, the diffusivity at 1130 °C is at least two times larger than that at 1100 °C. In addition, we also studied the time dependence of the Li-poor-VTE-induced reduction of Li 2O-content on surface of the same MgO-doped crystal. The results show that the surface Li 2O-content reduction induced has a square-root dependence on the VTE duration. Based upon this dependence, the mathematical solution to the Li + diffusion equation, an integral of error function complement, is obtained and verified by the experimental result. It is concluded that the MgO doping has less effect on both the Li + diffusivity and the dependence of surface Li 2O-content reduction on the VTE duration. © 2012 Elsevier B.V. All rights reserved.

Research Area(s)

  • Li-poor VTE, Li + diffusivity, LiNbO 3 crystal, MgO (5 mol%), Surface composition

Citation Format(s)