Structural and magnetic investigations of the Peierls transition of α-(Per)2M(mnt)2 with M = Fe and Co

V. Gama; R. T. Henriques; M. Almeida; C. Bourhonnais; J. P. Pouget; D. Jérôme; P. Auhan-Senzier; B. Gotschy

doi:doi:10.1051/jp1:1993268

Numéro		J. Phys. I France Volume 3, Numéro 5, May 1993


Page(s)		1235 - 1244
DOI		https://doi.org/10.1051/jp1:1993268

DOI: 10.1051/jp1:1993268
J. Phys. I France 3 (1993) 1235-1244

Structural and magnetic investigations of the Peierls transition of $\alpha$ -(Per) $_{\rm {2}}$ M(mnt) $_{\rm {2}}$ with M = Fe and Co

V. Gama¹, R. T. Henriques¹, M. Almeida¹, C. Bourhonnais², J. P. Pouget³, D. Jérôme³, P. Auhan-Senzier³ and B. Gotschy³

¹ Laboratorio Nacional de Engennaria e technologia Endustrial, Departamento de Quimica, P- 2685 Sacavem, Portugal
² Dtpartement de physique, Universitt de Sherhrooke, Sherbrooke, Qutbec, JIK 2R1, and Laboratoire de Physique des Solides (CNRS URA 2), Universitt de Paris-Sud, Bstiment 510, Orsay, F-91405, France
³ Laboratoire de Physique des Solides (CNRS URA 2), Universitt de Paris-Sud, Batiment 510, Orsay, F-91405, France

(Received 18 September 1992, revised 7 January 1993, accepted in final form 16 January 1993)

Abstract
In this work we present and discuss the temperature variation of X-ray, EPR and nuclear spin-lattice relaxation rate measurements for the two quasi-one-dimensional compounds $\alpha$ -(Per) $_{\rm {2}}$ Fe(mnt) $_{\rm {2}}$ and $\alpha$ -(Per) $_{\rm {2}}$ Co(mnt) $_{\rm {2}}$ . From X-ray and EPR intensity data, a Peierls instability of the Perylene stacks is found to take place at 58 K and 75 K for the Fe and Co derivatives respectively. In contrast to other members of this series of two-chain compounds, the M(mnt) $_{\rm {2}}$ , stacks are found to play no role in the Peierls instability. As for diffusive excitations of localized spins in dimerized Fe(mnt) $_{\rm {2}}$ , stacks, their influence is shown to dominate the temperature variation of both the spin-lattice nuclear relaxation rate and the previously measured Faraday spin susceptibility.

Structural and magnetic investigations of the Peierls transition of -(Per) M(mnt) with M = Fe and Co

Structural and magnetic investigations of the Peierls transition of $\alpha$ -(Per) $_{\rm {2}}$ M(mnt) $_{\rm {2}}$ with M = Fe and Co