Experimental Correlation between Nonlinear Optical and Magnetotransport Properties Observed in Au-Co Thin Films

Abstract

Magnetic materials where at least one dimension is in the nanometer scale typically exhibit different magnetic, magnetotransport, and magnetooptical properties compared to bulk materials. Composite magnetic thin films where the matrix composition, magnetic cluster size, and overall composite film thickness can be experimentally tailored via adequate processing or growth parameters offer a viable nanoscale platform to investigate possible correlations between nonlinear magnetooptical and magnetotransport properties, since both types of properties are sensitive to the local magnetization landscape. It has been shown that the local magnetization contrast affects the nonlinear magnetooptical properties as well as the magnetotransport properties in magnetic-metal/nonmagnetic metal multilayers; thus, nanocomposite films showcase another path to investigate possible correlations between these distinct properties which may prove useful for sensing applications.

Magnetic and Optical Properties of Au–Co Solid Solution and Phase-Separated Thin Films and Nanoparticles

“…Nanomaterials possessing combined magnetic and plasmonic properties have recently emerged as enticing functional materials in various applications including cancer detection and treatment, − magnetic resonance imaging, , data storage, and mechanochromic devices . These properties are predominantly achieved with nanoparticles in the Fe 3– x O 4 material system, though Au-Co also demonstrates this bifunctionality, in addition to attractive catalyst capabilities. , The majority of research on Au-Co nanoparticles has been focused on nanoparticles achieved via chemical growth techniques; − recently, functional Au-Co nanoparticles have also been achieved through laser ablation. , Research in the thin-film configuration have been studied as multilayers for data storage, and mixed as-deposited thin films, via evaporation − and sputtering − with much of the focus on the material structure, , which has been observed as a solid solution, amorphous, and a solid solution with interspersed Au and Co particles.…”

Tailoring the magnetic anisotropy of cobalt-gold thin lms

“…A Co concentration below 40% causes a small amount of magnetic clusters, leading to a decrease in K ax . Briefly, increase in Co concentration leads to increased axial anisotropy until an optimal value is reached, beyond which it decreases again since the magnetic clusters have now coalesced and percolated [17,27,28]. We also performed XRD measurements to support the Co cluster formation in Co 0.4 Au 0.6 thin films, which can be seen in Figure 3.…”

“…Although extensive work has been carried out regarding the magnetotransport and magnetooptical properties of Au-Co films [17,23,24], the FMR study of Co-Au thin films has not been investigated to the best of our knowledge. Hence, room temperature ferromagnetism in Co x Au (1−x) thin film alloys where x = 0.25, 0.33, 0.40, 0.48, and 0.61 on silicon (100) substrate has been observed by FMR.…”

“…Strong enhancement of the magnetooptical activity was observed when surface plasmon polaritons were excited in the nanocomposite films. In another study on Co-Au cosputtered thin films, it was revealed that the local magnetization contrast affects the nonlinear magnetooptical properties as well as the magnetotransport properties in magnetic metal/nonmagnetic metal multilayers; thus, nanocomposite films showcase another path to investigate possible correlations between these distinct properties, which may prove useful for sensing applications [17].…”