Self-Diffusion of Lithium, Hydrogen, and Oxygen Ions in Crystalline Lithium Hydroxide
Abstract—The self-diffusion coefficients of ions of the three chemical elements forming lithium hydroxide have been determined by the crystal–crystal and crystal–gas isotope exchange method in the temperature range 500–720 K. Crystal samples with different isotope compositions have been grown by the Bridgman method from melts. The melting temperature is 743 ± 2 K. Original methods have been developed for high-precision measurements of the isotope ratios of all the three elements, i.e., lithium (6Li/7Li), hydrogen (H/D), and oxygen (16O/18O), and their changes after diffusion annealing with the use of the same sample. The self-diffusion coefficients of lithium and hydrogen ions differ but by a factor of no more than 3–5; however, their magnitudes exceeds those for oxygen by several orders of magnitude. In particular, at 670 K, they are equal to 6.0·10-9 , 3.2·10–9, and 2.0·10–12 cm2 s–1 for hydrogen, lithium, and oxygen, respectively. In the range 680–720 K, the self-diffusion coefficients of hydrogen and lithium increase sharply with increasing temperature to approximately 10–6 cm2 s–1. A probable mechanism of migration of protons and lithium ions in LiOH and the role played in this process by the oxygen ions with a lower mobility have been discussed.
DOI: 10.1134/S1063783410100070
Correction of the equation (5) in
Self-Diffusion of Lithium, Hydrogen, and Oxygen Ions in Crystalline Lithium Hydroxide 2010 Vol. 52, No.10, 2044-2057 (the correction elated to third member in (5) on P.2054)
Исправление формулы (5) в статье
ФТТ 2010 Том 52 вып 10 на стр 1917
Full article in English is here
Self of Lithium, Hydrogen, and Oxygen Ions in Crystalline Lithium Hydroxide.PDF
Full article in Russian is here
Самодиффузия ионов лития, водорода и кислорода в кристаллическом гидроксиде лития.PDF