Although the unusual microstructural and electronic properties of charge density wave (CDW) modulated compounds have been extensively investigated over the past two decades, many aspects of the complex behaviour of these systems remain unexplained. As a result, the characterization of a new family of CDW structures, in which the CDW properties can be widely varied in a predictable manner, is of experimental and theoretical interest.The Nb3X4 (X = S, Se, Te) family of compounds is based on a hexagonal unit cell built up of edge and face sharing NbX6 octahedra (Figure 1). The structure is characterized by zigzag Nb-Nb chains and large hexagonal tunnels running parallel to the c-axis. One member of this family, Nb3Te4, is known to undergo a CDW phase transition at ∼100 K. A large number of metal atoms can be introduced into the tunnels to form a family of isostructural, intercalated compounds AyNb3X4. Electrical resistivity measurements on polycrystalline pellets of InyNb3X4 (X = Se, Te) have revealed temperature anomalies indicative of the formation of CDW in these materials.
Characterization of the torsional piezoelectriclike response of tantalum trisulfide associated with charge-density-wave depinning