New Polytype of the Quasi-One-Dimensional Conductor NbS3 with a High-Temperature Charge Density Wave

A new polytype of the quasi-one-dimensional conductor NbS3 with high-temperature charge density waves has been synthesized. The transmission electron microscopy study at room temperature has revealed only one of the two superstructures existing in the previously studied monoclinic phase with the period along chains close to b/0.352. In addition, a new incommensurate distortion of the lattice with the period close to 2b has been observed. The transport properties of the samples under study are in agreement with the study of the superstructure. The main lattice constants are somewhat different from the respective parameters in the previously studied monoclinic phase. The new phase can assumingly be intermediate between the two main known phases of NbS3, monoclinic and triclinic. Its properties can be explained within a model where a unit cell of the monoclinic phase can be considered as the superposition of unit cells of the triclinic phase.