Ostapiuk T. Phase equilibria and properties of intermediate phases in the Сu(Ag)2Se – Cd(Pb)Se – As(Sb)2Se3 and Сu2Se – Ge(Sn)Se2 – Sb2Se3 systems and related to them

Seven isothermal sections of the Сu(Ag)2Se – Cd(Pb)Se – As(Sb)2Se3 systems at 620 K, Сu(Ag)2Se – Ge(Sn)Se2 – Sb2Se3 at 620 K and 570 K have been constructed for the first time, 9 phase diagrams and 14 polythermal sections of the Сu(Ag)2Se – Cd(Pb)Se – As(Sb)2Se3, Сu2Se – Ge(Sn)Se2 – Sb2Se3 systems, as well as related ones, 4 liquidus surface projections of the Сu2Se – Ge(Sn)Se2 – Sb2Se3, Сu2Se – Cd(Pb)Se – As(Sb)2Se3 systems on the concentration triangle have been built based on the results of this work. For the first time, the crystal structure of the Cu12-хZn(Cd,Fe,Co,Ni)хAs(Sb)4S(Se)13 compounds, for x = 1.848, has been determined by the powder method. The crystal structure of quaternary compounds Cu10.26Mn1.92As4S13, Cu10.32Co1.8As4S13 (Sp. Gr. I-43m, a = 1.01800 (12) nm) has been studied by the single crystal method for the first time. The liquidus surface projection of the Cu2Se – CdSe – Sb2Se3 quasi-ternary system onto the concentration triangle has been constructed. For the AgSbSe2; Ag90Sb90Pb10Se190; Ag80Sb80Pb20Se180; Ag70Sb70Pb30Se170; Ag60Sb60Pb40Se160 single crystals from the region of primary crystallization of solid solutions based on AgSbSe2, as well as Ag8Sb8Pb92Se108; Ag5Sb5Pb95Se105; PbSe single crystals from the area of primary crystallization of solid solutions based on PbSe values of electrical conductivity at T = 300 K and thermoelectric coefficient have been measured. It has been shown that electrical conductivity with increasing of PbSe content decreases from 1.4 Ω-1∙cm-1 for AgSbSe2 till 10-2 Ω-1∙cm-1 for the Ag65Sb65Pb35Se165 single crystal. Increasing of the PbSe content has increased the thermoelectromotive force coefficient from 530 mV/К for AgSbSe2 till 1100 mV/К for Ag65Sb65Pb35Se165 single crystal. The investigated samples have got p-type of conductivity. The Ag8Sb8Pb92Se108; Ag5Sb5Pb95Se105 single crystals possess the high parameter of the thermoelectromotive force coefficient (≈60–220 mV/К). It has been shown that electrical and thermoelectric properties of the solid solutions based on AgSbSe2 or PbSe in AgSbSe2 – PbSe system can be changed with changing the composition.