CALCULATIONS OF POINT DEFECT PROPERTIES.Disorder in Pure and Doped Strontium Chloride

Abstract

RCsumC.-Nous prtsentons une etude thtorique sur les proprietts des dtfauts dans le chlorure de strontium pur et dope par cations monovalents. Nous examinons les defauts intrinskques trouvant que l'energie de formation d'un defaut du type Frenkel anionique est en bon accord avec les valeurs experimentales. Nous montrons que les defauts du type cation alkalin interstitiel sont importants aux basses temperatures dans des cristaux dopes par chlorides alkalins.

Point defect parameters for strontium chloride from ionic conductivity studies

“…The vaIue of hF from the HADES calculation [13] is consistent with our results, however, both the calculated Ah, and Ahi are much lower. For Ahj this is somewhat surprising since the HADES calculations for the alkaline earth fluorides give values in good agreement with experiment 12, 17, 181.…”

“…It has a relatively low melting point and is less reactive to O2 and H 2 0 than the alkaline earth fluorides. Investigations of this compound have included conductivity studies [4-91, neutron scattering experiments 110-121, a HADES calculation of the defect energies [13] and a molecular dynamics simulation of the fast-ion conduction [14, 151. In this paper we report conductivity results which have been computer analysed in an attempt to provide the first comprehensive set of defect parameters for SrC12.…”

A model for the onset of fast-ion conduction in fluorites

“…For BaF2 an extra Ba2+-B a2+ interaction was added to the potential to improve the fit to the known physical properties. The potential used for SrCl2 was developed by Hooton (I. E. Hooton, personal communication 1983) although test calculations showed only marginal differences in defect energies when the potential of Bendall & Catlow (1980) was used. The modelling of (3-PbF2 proved difficult, and the calculations that are reported below used the Sahni & Jacobs (1983) potential modified by hardening the Pb2+-F~ interaction, as described by , and by including a Pb2+-P b 2+ interaction F33(r) = 8058.4435 eV exp ( -r / 0.32111 Af) -99.4926 eV/(r/A)6, (19) where subscript 3 denotes the Pb2+ shell.…”

Analysis of the Transport Properties of Alkaline-earth Halides MX₂ (M = Ca, Sr, Ba, and X = F, Cl, Br) by Simulation with a Polarizable Ion Model

“…1,2 First, Rahman simulated CaF 2 using the numerical values for the repulsive part of the potential obtained by Kim and Gordon. 13,14 Dixon and Gillan then simulated CaF 2 and SrCl 2 using the rigid ion part of the shell model for alkaline-earth halide crystals developed by Catlaw et al 15,16 On the other hand, de Leeuw performed simulations using a modified CaF 2 rigid ion model by Benson and Dempsey. 17,18 Whereas Rahman, Dixon and Gillan focused on studying the superionic phases, de Leeuw was more concerned with the structure and properties of the liquid state of SrCl 2 .…”