Evolution of Interface Magnetism in Fe/Alq3 Bilayer Structure; Thickness-Dependent Interface Resolved Studies Under X-Ray Standing Wave

TL;DR

This study investigates how the magnetic properties at the Fe/Alq3 interface change with Fe thickness using advanced x-ray techniques, revealing symmetry-based perpendicular magnetic anisotropy and strain effects.

Contribution

It introduces an isotope-sensitive, depth-resolved x-ray standing wave method to analyze interface magnetism in metal-organic bilayers, highlighting thickness-dependent magnetic and structural behaviors.

Findings

Symmetry-based perpendicular magnetic anisotropy appears at lower Fe thickness.

Strain at the interface relaxes with increasing Fe thickness.

Deep Fe diffusion into Alq3 layer is observed.

Abstract

In the present work, interfacial magnetism at metal organic interface is probed using an isotope sensitive interface resolved nuclear resonance scattering technique which is made depth selective under x-rays standing wave conditions. Using GIWAXS and GINRS measurements, this study evidences the presence of symmetry-based PMA which appears at a lower thickness of Fe having distortion in cubic symmetry and disappears at a higher thickness of Fe as its cubic symmetry retains. The non-zero value of quadrupole splitting evidences the strain at the interfacial region which on increasing thickness of Fe relaxes. The diffusion of Fe is traced using XRF and NRR, deep penetration of Fe in Alq3 layer due to soft nature of the organic film is obtained. This thickness-dependent study enables us to understand the magnetic behavior of buried ferromagnetic metal in the vicinity of organic molecules.