Defect structure dependence on composition in lithium niobate

Abstract

The lattice constants of stoichiometric LiNbO3 and congruent

NMR Analysis of Mg Ion Localization in LiNbO3Crystal

“…According to [25] the integral intensity of this line makes up 6% from the intensity of the main line of 93 Nb NMR spectra central transition and these results are considered as the most serious arguments in favor of so-called "niobium vacancy" model [26]. However, later investigations of near-congruent LN crystals showed that relative integral intensity of this line makes up (0.9 ± 0.4)% [27].…”

Spin-Hamiltonian Parameters For CrLi 3+ Doped In LiNbO3

“…For LiNbO 3 :Cr Li 3+ we have [12] two different distances between Li ion and two triangles of oxygen ions: upper and lower triangles [11]. The distance between Li and upper oxygen triangle ions R H1 is 2.238 Å and the same distance for the lower oxygen triangle R H2 is 2.068 Å [24].…”

Behavior of Impurities In and Cd in the LiNbO<SUB>3</SUB>-LiTaO<SUB>3</SUB> System

“…LiNbO 3 and LiTaO 3 adopt an ilmenite (FeTiO 3 )-related structure 3) (not the perovskite structure) because of the similar ionic sizes of Li + (76 pm), Nb 5+ (64 pm), and Ta 5+ (64 pm). 4) These oxides undergo only one structural phase transition (corresponding to a ferroelectric-to-paraelectric phase transition) at temperatures (T C ) of 1483(10) K 5) and 938(5) K, 6) respectively.…”

“…Lithium niobate, LiNbO 3 , and isostructural lithium tantalate, LiTaO 3 , are ferroelectric and are known as, for example, important non-linear optic materials. Numerous studies on these materials have been conducted so far.…”

“…The average Li position is on the upper-triangle oxygen base of the octahedron; the Li ion is disordered and occupies the previously empty octahedron half of its time (dynamic disorder) or in half of the unit cells (static disorder). 1,2) In a recent theory of the ferroelectric transition in LiNbO 3 , it is assumed that the dynamic order-disorder of Li ions (Fig. 2) is the driving mechanism.…”