J. Phys. IV France
Volume 114, April 2004
Page(s) 517 - 519

J. Phys. IV France
114 (2004) 517
DOI: 10.1051/jp4:2004114121

Incommensurate structure and the superconducting properties of the organic superconductor (MDT-ST)(I $\mathsf{_{3})_{0.417}}$

T. Kawamoto1, 1, T. Mori1, T. Terashima2, S. Uji2, H. Kitagawa3, K. Takimiya4, A. Takamori4 and T. Otsubo4

1  Department of Oragnic and Polymeric Materials, Tokyo Institute of Technology, Tokyo 152-8552, Japan
2  National Institute for Materials Science, Tsukuba, Ibaraki 305-0003, Japan
3  Department of Chemistry, Kyushu University, Fukuoka 812-8581, Japan
4  Department of Applied Chemistry, Hiroshima University, Hiroshima 739-8527, Japan

The charge-transfer degree and the superconducting properties of the organic superconductor (MDT-ST)I $_{1+\delta }$ have been studied [ MDT-ST: 5 H-2-(1,3-dithiol-2-ylidene)-1,3-diselena-4,6-dithiapentalene] . The Raman spectrum and the x-ray oscillation photograph show that the polyiodide chain is composed of I 3-, which is incommensurate to the donor lattice. The chemical composition is determined to be (MDT-ST)(I 3)0.417. The upper critical fields are within the Clogston-Chandrasekhar paramagnetic limit in all directions, and the coherence lengths are longer than the thickness of the conducting sheet. Key words. Organic superconductor - incommensurate crystal - upper critical field.

© EDP Sciences 2004