Programme

P.57 -- Poster, VCTP-48

Date: Thursday, 3 August 2023

Time: 08:30 - 10:00

Impact of screening and relaxation in weakly coupled 2D macromolecular heterostructures: implications for switchable molecular spin-coupling

E. Rauls (1), T.T. Nhung Nguyen (2), T. Sollfrank (2), C. Tegenkamp (2), and U. Gerstmann (3)

(1) Institute of mathematics and physics, University of Stavanger; (2) Institute of physics, TU Chemnitz; (3) Theoretical physics, University of Paderborn

Phthalocyanines (Pc) at surfaces are prototype molecules which can host magnetic ions in a well-defined surface environment. The precise external control of the individual spins via electric fields, however, require a detailed knowledge of the influence of the substrate. In a combined experimental and theoretical study, we have investigated the structural and electronic properties of Pb and Mn-phthalocyanines adsorbed on three different graphene-related substrates. Formation of almost identical densely packed PbPc molecular layers with strongly tilted molecules were found on both n-type and p-type doped 2D templates. On HOPG, in contrast, the dispersing molecular states of the less deformed molecular adsorbate stress the importance of substrate mediated interaction and proximity coupling [1]. Substituting Pb by Mn triggers the magnetic coupling within the molecular monolayer. The adsorption on either epitaxial or pyrolytic graphene leads to interesting differences in the adsorption behavior and the resulting electronic and magnetic properties. The different deformation ability of the vdW coupled systems, like their actual thickness and buckling, triggers the molecular morphology and exhibits a proximity coupled band structure. Like this, it provides important implications for future 2D design concepts of molecules at surfaces for sensing as well as information storage devices. [1] T.T. Nhung Nguyen, T. Sollfrank, C. Tegenkamp, E. Rauls, U. Gerstmann, Phys. Rev. B 103, L201408 (2021).

Presenter: Rauls Eva