Antonyshyn I. Interaction of gallium and antimony with transition (V, Mn) and rare-earth (Y, La, Ho) metals

The component's interaction in the ternary {V, Mn}-Ga-Sb and {Y, La, Ho}-Ga-Sb systems has been investigated using X-ray methods for the first time, and their phase diagrams at 500 oC and 0-85 at. % Ga have been constructed. The crystal structure of the binary compound Mn6Ga29 has been finally determined for the first time, and the existence of three polymorphic modifications has been observed. The crystal structures of alpha- and beta-modifications have been determined using single crystal data, whereas the structure of gamma-Mn6Ga29 has been defined by well-resolved X-ray synchrotron powder data. In the ternary systems the extended solid solutions based on the binary compounds have been studied: V3GaxSb3-x (structure type Cr3Si, x = 0-0.68), VGaxSb2-x (CuAl2, x = 0-0.23), Y5GaxSb3-x (Mn5Si3, x = 0-2.8), La5Ga3-xSbx (Ba5Si3, x = 0-0.64), Ho5GaxSb3-x (Mn5Si3, x = 0-2.36). The binary antimonide Mn1+xSb dissolves a significant amounts of gallium that accompanied by the NiAs-Ni2In structure change. Seven new ternary compounds have been synthesized for the first time, and the crystal structure of Ho5GaSb3 and Y5Ga1.09Sb2.91 has been determined using X-ray single crystal data. Ternary compound Ho5GaSb3 crystallizes with orthorhombic structure of own type closely related to the Sm5Ge4 type. The isostructural compounds R5GaSb3 (R = Y, Gd-Tm) have been obtained for the first time. The homogeneity ranges, melting and decomposition points have been determined for a number of ternary compounds. The component's interaction in the ternary {Y, La, Ho}-Ga-Sb and relative R-Ga-Sb (R - rare-earth metal) systems has been compared. The crystal chemical peculiarities of new Mn6Ga29, Mn2Ga9Sb0.43 Ho5GaSb3 and La12Ga3.26Sb24.02 structures have been analyzed.