Large-Area Nanopillar Arrays by Glancing Angle Deposition with Tailored Magnetic Properties

Abstract

Ferromagnetic films down to thicknesses of tens of nanometers and composed by polycrystalline Fe and Fe2O3 nanopillars are grown in large areas by glancing angle deposition with magnetron sputtering (MS-GLAD). The morphological features of these films strongly depend on the growth conditions. Vertical or tilted nanopillars have been fabricated depending on whether the substrate is kept rotating azimuthally during deposition or not, respectively. The magnetic properties of these nanopillars films, such as hysteresis loops squareness, adjustable switching fields, magnetic anisotropy and coercivity, can be tuned with the specific morphology. In particular, the growth performed through a collimator mask mounted onto a not rotating azimuthally substrate produces almost isolated well-defined tilted nanopillars that exhibit a magnetic hardening. The first-order reversal curves diagrams and micromagnetic simulations revealed that a growth-induced uniaxial anisotropy, associated with an anisotropic surface morphology produced by the glancing angle deposition in the direction perpendicular to the atomic flux, plays an important role in the observed magnetic signatures. These results demonstrate the potential of the MS-GLAD method to fabricate nanostructured films in large area with tailored structural and magnetic properties for technological applications.

The Relationship between Annealing Temperatures and Surface Roughness in Shaping the Physical Characteristics of Co40Fe40B10Dy10 Thin Films

“…Furthermore, rougher surfaces have a higher carrier conductivity, which reduced electrical resistance. following the annealing of the film, primarily due to a slight improvement in exchange coupling [60,61]. The larger area of the magnetic domain produces stronger magnetization, which is consistent with the χac result.…”

“…The average stripe magnetic domain increases about from 2 µm to 5 µm in width size when the annealing temperature is elevated to 300 • C. The features of domain structures are thought to have a substantial impact on magnetic behavior. The continuity and contrast of magnetic domains experience enhancements following the annealing of the film, primarily due to a slight improvement in exchange coupling [60,61]. The larger area of the magnetic domain produces stronger magnetization, which is consistent with the χ ac result.…”

Structure and Void Connectivity in Nanocolumnar Thin Films Grown by Magnetron Sputtering at Oblique Angles

“…The last years have witnessed the flourishing of numerous applications and technological devices based on nanocolumnar porous, thin films [1]. These are formed by nanocolumns with a typical diameter and side-to-side distance in the order of 100 nm, making these materials less dense and with a much larger specific surface than their compact counterpart [2][3][4], and with different optical, electrical, and magnetic properties [5][6][7][8][9][10][11][12]. These features make them good candidates for the development of numerous technological devices, such as gas or liquid sensors, optical coatings, and electrodes or instruments for fluid manipulation, among others [13][14][15][16][17][18][19][20][21][22][23][24][25][26].…”

Electroless Cobalt Deposition on Dealloyed Nanoporous Gold Substrate: A Versatile Technique to Control Morphological and Magnetic Properties

“…A multiplicity of advanced fabrication techniques have been designed, combined together, and successfully used to tailor magnetic thin films to usage needs. Such techniques are mainly based on top-down approaches such as lithography and etching or on bottom-up approaches involving deposition and self-assembly processes [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ].…”