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Growth of single phase, single crystals of V9O17

1981; Elsevier BV; Volume: 36; Issue: 2 Linguagem: Inglês

10.1016/0022-4596(81)90148-1

1095-726X

H. Kuwamoto, N. Ōtsuka, Hiroshi Sato,

Polyoxometalates: Synthesis and Applications

Single crystals of Magnéli phase V9O17 were successfully grown for the first time by a vapor transport technique utilizing TeCl4 as a transport agent. No trace of syntactically intergrown V8O15 could be detected in these crystals. The structure is triclinic and is homologous to other Magnéli phase compounds VnO2n−1 (n = 3 ∼ 8). The lattice parameters (of the reduced cell) measured are a = 7.009 Ȧ b = 14.518 Ȧ c = 5.418 Ȧ α = 95.5 ° β = 108.9 ° γ = 83.1 ° This compound manifests a metal-insulator transition as in other Magnéli phase compounds. The transition temperature has been determined to be 79 K. At and below the transition point down to 16 K, at which an anomalous peak in the resistivity exists, a time dependence of resistivity at fixed temperatures is found. The existence of V10O19 was also confirmed by transmission electron microscopy in a material produced under highly nonequilibrium conditions, intergrown in the matrix of V9O17 in a microsyntactoc fashion. The existence of V10O19 has never been reported.