ESR STUDY OF ORIENTED LITHIUM PHTHALOCYANINE THIN-FILMS ON GLASS SUBSTRATE

Thin films of lithium phthalocyanine (PcLi) were prepared by vacuum de position on a glass substrate at various substrate temperatures. Modif ications of the electron spin resonance signal (shape, position) with the substrate temperature are evidenced and explained by means of the x-like --> alpha phase transformation. Moreover, thin films deposited on glass substrate show a strong preferential ordering of the molecule s forming columns which are lying in the plane of the substrate, the r esulting orientation of the molecules being almost perpendicular to th e substrate plane. This preferential ordering results in an anisotropi c spin transport depending upon the substrate temperature. It is demon strated that the demagnetizing field can account for the temperature d ependence and the angular variation of the g-factor in PcLi thin films . (C) 1997 Elsevier Science S.A.