Growth and Characterization of a CoTPP/NiO(001) Antiferromagnetic Spinterface

Abstract

Interfaces between molecular layers and ferromagnetic materials, also called spinterfaces, are the test bed for the development of molecular spintronics, unveiling new effects and opportunities for novel potential applications. Among several combinations of materials that have shown intriguing behaviors, spinterfaces based on antiferromagnetic materials received much less consideration, despite the dramatic increase in attention recently drawn by the antiferromagnetic declination of spintronics. In this work, an antiferromagnetic spinterface based on the transition metal oxide NiO, a widely studied antiferromagnetic insulator with one of the highest critical temperatures, has been realized and characterized. As for the molecular counterpart, Co tetraphenyl porphyrin (CoTPP) is a very promising choice, being sublimable in vacuum and paramagnetic. CoTPP/NiO(001) spinterfaces are experimentally investigated with respect to their morphology, structure, electronic, and magnetic properties. Theoretical calculations have also been performed to circumstantiate and support the measurements. Although characterized by a relatively weak interface coupling, spin-dependent hybridization is observed at the interface, which makes the CoTPP/NiO a perfect system for initiating the exploration of a molecular antiferromagnetic spintronics.