The magnetic-field dependence of the metal-to-insulator transition temperature, (Formula presented), in the quasi-one-dimensional systems (Formula presented), with (Formula presented), was studied by magnetoresistance measurements under fields up to 18 T. In the Pt compound, our results show that (Formula presented) is anisotropic: (Formula presented) decreases as (Formula presented) up to 18 T with a slope similar to that found in the Au compound when the magnetic field is applied parallel to the chain axis, while (Formula presented) decreases faster and does not follow a pure (Formula presented) dependence when the magnetic field is applied perpendicular to the chain axis. This anisotropy of the field dependence denotes the coupling of the Peierls transition in the perylene chains to a spin-Peierls-like transition in the Pt(Formula presented) chains, correlated with an anisotropic magnetic susceptibility, while in the Au compound a pure Peierls transition takes place.
|Number of pages||7|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 1 Dec 1996|