Electronic properties and magnetic interaction of metal organic molecules on a monolayer thick GdAu2 substrate

Trabajo presentado en el X Iberian Conference on Tribology y XI Iberian Vacuum Conference (IBERTRIVA) celebrada en Sevilla (España), del 26 al 28 de junio de 2019
Fundamental research on new states of the matter and technological applications in fields like spintronics (1) relays on the interfaces between magnetic materials and other states of the matter like superconductors, semiconductors or topological insulators. In the case of twodimensional (2D) ferromagnetic materials, it is necessary to keep the long-range magnetic order. To maintain this 2D magnetism the chemical and structural stability is mandatory. A molecular overlayer could influence these properties due to charge transfer. 2D rareearth/Noble-metal monolayer alloys show great potential as nanostructured magnetic patterns. Many of the lanthanides have shown already its potential by forming highly ordered corrugated structures when deposited on Au(111) and Ag(111) (2) nevertheless their magnetic and electronic structure after molecular deposition remains unknown. Here, we show evidence of the interaction between a GdAu2 monolayer alloy and magnetic molecules (metal centered porphyrin and phthalocyanines) that mutually influence their magnetic behavior. For example in the case of a one monolayer (ML) Co-tetraphenylporphyrin we observe a ferromagnetic interaction of the Co atom to the substrate, while the underlying material keeps basically its electronic and magnetic properties (Fig. 1). On the other hand a ML thick Co-phthalocyanine molecules film does not reveal any magnetic interaction. Only the second layer show a small magnetic signal.