The thermodynamic characteristics of formation of ternary sulfides MeLn2S4 and solid solutions based on them

Sulfide ceramic materials based on CaYb2S4 with functional electrolytic properties

“…Most likely, the formation of the solid solutions based on the CaYb 2 S 4 ternary compound in the system under investigation is accompanied by the formation of ionized vacancies according to Eqs. (10) and (11). Furthermore, the performed investigation demonstrated that the experimental density is equal to 95-98% of the theoretical density.…”

“…The introduction of the Yb 2 S 3 dopant at concentrations from 1 to 4 mol % leads to an increase in the electrical conductivity and the ion transport numbers and a decrease in the electron transport numbers, because the concentration of ion defects according to reaction (10) increases. It is evident that, for these compositions, the number of ionized vacancies with respect to sulfur and metal atoms corresponds to the notion of "dilute solution" [11].…”

“…(i) in the case of complete ionization of defects, we have (9) (10) where and are the triply and doubly ionized negatively charged vacancies in the ytterbium and calcium sublattices, respectively, and (ii) in the case of incomplete ionization of defects due to the polyvalence of ytterbium, we can write (11) (2) The mechanism of disordering can be described by the following equations:…”

“…The ionic component of the electrical conductivity was divided into the cationic and anionic components in concentration circuits (4) and (5) [10]. The isothermal dependences E S = f(E Ca ) for the electrolytes of different compositions are plotted in Fig.…”

Electronic and optical properties of ASc2S4 (A = Ca, Sr) compounds

“…As can be seen from the literature, the AB 2 O 4 -type compounds are very popular. However, the Oxygen (O) atoms in the AB 2 O 4 -type structures could be replaced with Sulphur (S) atoms belonging to chalcogens as O-atoms, and there are few studies in the literature about this structure (AB 2 S 4 ) [1,[12][13][14][15][16]. In this study, the ASc 2 S 4 (A=Ca, Sr) compounds, synthesized experimentally [17], are investigated using Density Functional Theory calculations.…”