Abstract
The crystal structures, superstructures, dc conductivity, optical properties, and thermopower of six linear-chain conductors of the type [Pt(]⋅(M=Ni,Co,Zn,Fe,Mg,Mn), where M is a divalent metal (M=Ni,Co,Zn,Fe,Mg,Mn), have been studied. At high temperatures they form a common orthorhombic metallic phase (I) with conductivities of 30–200 (Ω cm and thermopowers of 5–10 μV/K, with the lattice weakly modulated by the one-dimensional Peierls distortion. Below , three compounds (Ni,Co,Zn) form a semiconducting phase (A-II) due to the ordering of the [M(O cations. As the cation superlattice is commensurate with the three-dimensional Peierls distortion, these salts transform at a lower temperature into a charge-density-wave phase (A-III). In the other three compounds (Fe,Mg,Mn), the cations order in a superlattice (phase B-II) which is incommensurate with both the average Pt-ion lattice and the three-dimensional Peierls distortion, and therefore no charge-density-wave state is formed. The influence of competing interactions is briefly discussed.
- Received 8 May 1986
DOI:https://doi.org/10.1103/PhysRevB.35.7835
©1987 American Physical Society