Magnetic behavior of periodic patterns of nickel microwires obtained by laser interference

CARLOS I. ZANDALAZINI; TAIMI ESPINOSA REYES; MAXIMILIANO ROSSA; MARCOS I. OLIVA

Puerto Varas

Workshop; Latin American Workshop on Magnetism, Magnetic Materials, & their Applications; 2023

Latin American Association of Magnetism

The magnetic behavior of low-dimensional materials has attracted considerable attention in the fields of sensors, energy storage, catalysis, and wastewater treatment. Among the topdown approaches to produce such structures, direct laser interference patterning (DLIP) stands out as a powerful method that allows the fabrication of periodic patterns with a variety of geometries and micrometric precision, while enabling the efficient use of laser output and scalability. In this work, we present a study on the shape-dependent magnetic anisotropy of periodic arrays of nickel microwires (MWs) prepared by a two-beam interference configuration of DLIP on sputter-deposited Ni thin films. Both intact Ni thin films and laser-patterned MWs were characterized by X-ray diffraction, scanning electronic microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and vibrating-sample magnetometry. The geometries and dimensions of individual nickel MWs, their surface oxidation state, as well as the periodicity of the whole MW patterns, were characterized in detail to obtain a better understanding of the role of shape anisotropy on the magnetic properties of interest. The magnetic properties were studied as a function of the magnetic field orientation (from parallel to perpendicular to the axes of the MWs) and different wire aspect ratios (width/length). The angular dependence of both the saturation field and coercivity allows us to infer about sensitivity of the magnetization reversal mechanism (and squareness, SQ, defined by the ratio of remanent magnetization and saturation magnetization MR/MS) to the MWs packing density.