Growth of Co Nanomagnet Arrays with Enhanced Magnetic Anisotropy

Abstract

A trigon structure formed by submonolayer gadolinium deposition onto Au(111) is revealed as a robust growth template for Co nanodot arrays. Scanning Tunneling Microscopy and X‐Ray Magnetic Circular Dichroism measurements evidence that the Co nanoislands behave as independent magnetic entities with an out‐of‐plane easy axis of anisotropy and enhanced magnetic anisotropy values, as compared to other self‐organized Co nanodot superlattices. The large strain induced by the lattice mismatch at the interface between Co and trigons is discussed as the main reason for the increased magnetic anisotropy of the nanoislands.

Influence of 4f filling on electronic and magnetic properties of rare earth-Au surface compounds

“…They all share a common, well-defined structure and excellent crystal quality with a RE-NM 2 stoichiometry, as a well as a hexagonal moiré with a nanoscale periodicity that is induced by the lattice mismatch between the RE-NM 2 monolayer and the noble metal substrate. This structural homogeneity among the series of lanthanides makes the RE-NM 2 monolayer a convenient platform to tune spin textures and magnetic properties of great interest in the field of spintronics 7 , while their chemical stability and moiré modulation convert these compounds into suitable magnetic templates to drive self-organized nanostructure growth [8][9][10][11] . At a more fundamental level, the crystal perfection and identical structure of the RE-NM 2 monolayer among the REs appear ideal to investigate the interplay between electronic properties and magnetism, that is, the connection between 4 f shell filling, f -d hybridization, RE atom valency and magnetic response in two dimensions.…”

Two-Dimensional Rare Earth–Gold Intermetallic Compounds on Au(111) by Surface Alloying

“…11,12 The structurally robust moiré lattices in GdAu2 has been reported as templates for well-aligned organic nanowires, 6 and dense arrays of Co nanodots. [13][14][15] In addition, two-dimensional ferromagnetic orders have been reported in these systems mainly originated from the 4f electrons in the rare earth atoms. 10,16 The curie temperatures are ~10 K and ~80 K for GdAu2 and GdAg2, respectively.…”

“…Lanthanide rare earth-based intermetallic compounds on noble metal surfaces are good examples of periodically modulated surfaces by surface alloying. Deposition of gadolinium (Gd) on hot Au(111) or Ag(111) gives rise to the formation of long-range ordered GdAu 2 and GdAg 2 . , The lattice mismatches in these systems results in periodically modulated moiré structures, leading to electronic modulations in these systems. , The structurally robust moiré lattices in GdAu 2 have been reported as templates for well-aligned organic nanowires and dense arrays of Co nanodots. − In addition, two-dimensional ferromagnetic orders have been reported in these systems mainly originating from the 4 f electrons in the rare earth atoms. , The Curie temperatures are ∼10 K and ∼80 K for GdAu 2 and GdAg 2 , respectively. Further, the reduced dimensionality gives rise to new exotic states in these systems.…”

High-Density Ordered Arrays of CoPt3 Nanoparticles with Individually Addressable Out-of-Plane Magnetization

“…In order to circumvent this problem, the NPs need to be separated by at least 2–5 nm, which has not been achieved by this method. Recently, a novel method of utilizing the Gd–Au hexagonal trigon phase formed on the Au(111) surface as a template to grow Co NPs into arrays has been introduced . However, whether this method can lead to the development of high-density memory devices is yet to be seen.…”

“…Recently, a novel method of utilizing the Gd−Au hexagonal trigon phase formed on the Au(111) surface as a template to grow Co NPs into arrays has been introduced. 24 However, whether this method can lead to the development of high-density memory devices is yet to be seen. The use of nanoporous templates with regularly ordered pores has appeal as a viable alternative approach for achieving BPM.…”