Open AccessThe Se2 (GAS) fugacity in systems with noble metals: chrisstanleyite Ag2Pd3Se4-naumannite Ag2Se-β-PdSe2 and luberoite Pt5Se4-sudovikovite PtSe2
Author(s) -
A. V. Kristavchuk,
A. Vymazalova,
Е. Г. Осадчий,
I. V. Vikentyev,
Д. А. Чареев,
Н. С. Бортников
Publication year - 2019
Publication title -
doklady akademii nauk. rossijskaâ akademiâ nauk
Language(s) - English
Resource type - Journals
ISSN - 0869-5652
DOI - 10.31857/s0869-56524856720-725
Subject(s) - fugacity , galvanic cell , chemistry , analytical chemistry (journal) , gas phase , electrolyte , materials science , electrode , environmental chemistry
The reactions of 6Ag(cr) + 3PdSe2(cr) = 2Ag2Se(cr) + Ag2Pd3Se4(cr) and 12Ag(cr) + 5PtSe2(cr) = 6Ag2Se(cr) + Pt5Se4(cr) were studied with the EMF method in a completely solid-state galvanic cell with an Ag ion-conducting solid electrolyte with overall gas space (Ar under atmospheric pressure). The EMF vs T dependencies were obtained in the temperature ranges of Т = 425-648 K and 501-713 K, respectively. Then, they were recalculated for gaseous Se fugacity in dependence on the temperature for non-variant equilibriums of Ag2Pd3Se4 (chrisstanleyite)-β-PdSe2 (the phase, which transforms into verbeekite under low temperatures)-Ag2Se (naumannite) and Pt5Se4 (luberoite)-PtSe2 (sudovikovite): logfSe2(gas)(Ag2Pd3Se4/Ag2Se/PdSe2) = 7.71 ± 0.05 - 8.524 ± 0.026(1000/T), logfSe2(gas)(Pt5Se4/PtSe2) = 7.135 ± 0.027 - 12.274 ± 0.016(1000/T).