Characterization of cation disorder and oxygen vacancies in Li‐rich Li₂TiO₃

Abstract

Li 2 TiO 3 has a broad stoichiometric range and wide application prospects such as cathode, tritium breeder, and microwave dielectric materials. Particularly, Li 2 TiO 3 shows a faster tritium release performance and exceptional chemical and radiation stabilities, making it one of the most promising solid breeder materials. Li-rich Li 2 TiO 3 has been developed for years as an advanced breeder material due to its enhanced tritium production and better stability in hydrogen atmosphere.However, the defect chemistry responsible for accommodating excess Li and how the non-stoichiometry improves the material's performance is still unclear. In this work, the crystal structure and non-stoichiometry-induced defects in Li-rich Li 2 TiO 3 were investigated by means of X-ray diffraction, electron spin resonance, and X-ray photoelectron spectroscopy. Results show that oxygen vacancies and cation disorder both play a major role in the incorporation of excess Li. The sintering atmosphere (air/vacuum) has a negligible effect on the formation of the non-stoichiometry-induced defects but will influence the concentration of the oxygen vacancies. The better stability in the reduction atmosphere may be ascribed to the oxygen vacancies inside the Li-rich Li 2 TiO 3 crystals.

Doping and luminescence mechanisms of broadband NIR‐II emitting Zn2(1−x)Ni2xGa3Ge0.75O8 nanoparticles

“…Their Zn–O and Ga–O bond lengths and cell volume as a function of Ni 2+ concentration were calculated and are listed in Table 1. It is found that the bond lengths related to Zn–O, Ga–O, and unit‐cell volume decrease with increasing Ni 2+ concentration due to the ionic radius of Ni 2+ being smaller than that of Zn 2+ , 19 further proving that Ni 2+ ions tend to replace Zn 2+ ions in ZGGO nanoparticles.…”

One‐step fabrication of Li2TiO3 ceramic pebbles using pulsed YAG laser

“…The intensity ratio of peak A and B, I A /I B , represents the degree of long-range cation ordering. 38,39 Although the I A /I B ratios were 2.4 and 0.0 in the simulated patterns from the perfect crystals of β-and γ-Li 2 TiO 3 , the ratios from the samples before and after irradiations were 2.0…”

“…This peak is designated as peak B in this paper, which is derived from the main peak of γ‐Li 2 TiO 3 from (2 0 0) plane as well as (1 3 3) and (2 0 2) planes in β‐Li 2 TiO 3 . The intensity ratio of peak A and B, I A / I B , represents the degree of long‐range cation ordering 38,39 . Although the I A / I B ratios were 2.4 and 0.0 in the simulated patterns from the perfect crystals of β‐ and γ‐Li 2 TiO 3 , the ratios from the samples before and after irradiations were 2.0 and 1.0, respectively.…”