%A Ovchinnikov,Alexander %A Bobev,Svilen %D 2020 %J Frontiers in Chemistry %C %F %G English %K Flux growth,pnictides,crystal structure,electronic structure,Metal clusters %Q %R 10.3389/fchem.2019.00909 %W %L %M %P %7 %8 2020-January-10 %9 Original Research %# %! Ba-V-Sb and Ba-V-As %* %< %T Exploration of Multi-Component Vanadium and Titanium Pnictides Using Flux Growth and Conventional High-Temperature Methods %U https://www.frontiersin.org/articles/10.3389/fchem.2019.00909 %V 7 %0 JOURNAL ARTICLE %@ 2296-2646 %X The flux growth method was successfully employed to synthesize millimeter-sized single crystals of the ternary barium vanadium pnictides Ba5V12As19+x (x ≈ 0.02) and Ba5V12Sb19+x (x ≈ 0.36), using molten Pb and Sb, respectively. Both compositions crystallize in space group P4̄3m and adopt a structure similar to those of the barium titanium pnictides Ba5Ti12Pn19+x (Pn = Sb, Bi), yet with a subtly different disorder, involving the pnictogen and barium atoms. Attempts to obtain an arsenide analog of Ba5Ti12Pn19+x using a Pb flux technique yielded binary arsenides. High-temperature treatment of the elements Ba, Ti, and As in Nb or Ta tubes resulted in side reactions with the crucible materials and produced two isostructural compositions Ba8Ti13−xMxAs21 (M = Nb, Ta; x ≈ 4), representing a new structure type. The latter structure displays fcc-type metal clusters comprised of statistically distributed Ti and M atoms (M = Nb, Ta) with multi-center and two-center bonding within the clusters, as suggested by our first-principle calculations.