It is well known that Pt shows much weaker plasmonic effects in the visible spectrum when compared to Au, Ag and Cu. Therefore, the realization of efficient optical absorption by Pt nanoparticles with sizes below 10 nm in the visible spectrum remains a challenge. One possible way to enhance the optical absorption is to prepare Pt-based bimetallic magnetic nanoparticles. Furthermore, if an external magnetic field is applied, the synergistic effect of both electric and magnetic fields may provide sufficient SERS enhancement. In this paper, CoPt hollow nanoparticles (NPs) with sizes below 10 nm and ultrathin shells (∼2 nm) were synthesized in solution, at room temperature. The NPs have high surface-to-volume ratios and excellent structural stability. The hollow NPs exhibited enhanced light absorption characterized by surface-enhanced Raman scattering (SERS) with 4-mercaptobenzoic acid (4-MBA) as tip molecules. It is noted that the SERS enhancement of these alloyed NPs can be tuned by using an external magnetic field. A synergistic optical effect between these hollow NPs and the Ag film substrate is obtained. Hence, CoPt hollow NPs show promise as SERS substrates and potential for other applications in optical enhancement.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/c8nr03781g | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A Schiff base-functionalized chitosan magnetic bio-nanocomposite for efficient removal of Pb (II) and Cd (II) ions from aqueous solutions.
Int J Biol Macromol
January 2025
Department of Chemistry, Faculty of Science, Arak University, Arak 38481-77584, Iran; Institute of Nanosciences &Nanotechnology, Arak University, Arak, Iran. Electronic address:
The rapid industrialization and human activities in catchments have posed notable global challenges in removing of heavy metal contaminants from wastewater. Here, Schiff-bases (SB) of cyanoguanidine (CG) and salicylaldehyde (SA) were covalently grafted on a magnetic nanocomposite of chitosan to form a hybrid magnetic nanostructure (FeO@CS-CGSB). The synthesized structure was characterized using various techniques such as Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), dynamic light scattering (DLS), zeta potential, and Brunauer-Emmett-Teller surface area analysis (BET).
View Article and Find Full Text PDFDiffusion coefficient measurements for moving samples under strong magnetic field gradients.
J Magn Reson
January 2025
São Carlos Institute of Physics, University of São Paulo São Carlos São Paulo Brazil.
Among the numerous measurements carried out during a well-logging procedure, the Nuclear Magnetic Resonance (NMR) assessment is one of the fundamental analyses in determining the economic viability of a well for the oil industry. Nowadays, two reliable approaches, Wireline Logging (WL) and Logging While Drilling (LWD), stand out. WL comprises the acquisition of NMR data under static conditions.
View Article and Find Full Text PDFActive Inference and Artificial Spin Ice: Control Processes and State Selection.
ACS Nano
January 2025
Department of Physics and Astronomy, University of Manitoba, Winnipeg R3T 2N2, Canada.
Theory and simulations are used to demonstrate implementation of a variational Bayes algorithm called "active inference" in interacting arrays of nanomagnetic elements. The algorithm requires stochastic elements, and a simplified model based on a magnetic artificial spin ice geometry is used to illustrate how nanomagnets can generate the required random dynamics. Examples of tracking and PID control are demonstrated and shown to be consistent with the original stochastic differential equation formulation of active inference.
View Article and Find Full Text PDFControllable -Polarized Spin Current in Artificially Structured Ferromagnetic Oxide with Strong Spin-Orbit Coupling.
Nano Lett
January 2025
Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
Realizing field-free switching of perpendicular magnetization by spin-orbit torques is crucial for developing advanced magnetic memory and logic devices. However, existing methods often involve complex designs or hybrid approaches, which complicate fabrication and affect device stability and scalability. Here, we propose a novel approach using -polarized spin currents for deterministic switching of perpendicular magnetization through interfacial engineering.
View Article and Find Full Text PDFDynamic Control of Weight-Update Linearity in Magneto-Ionic Synapses.
Nano Lett
January 2025
Centre de Nanosciences et de Nanotechnologies, CNRS, Université Paris-Saclay, 91120 Palaiseau, France.
Multifunctional hardware technologies for neuromorphic computing are essential for replicating the complexity of biological neural systems, thereby improving the performance of artificial synapses and neurons. Integrating ionic and spintronic technologies offers new degrees of freedom to modulate synaptic potentiation and depression, introducing novel magnetic functionalities alongside the established ionic analogue behavior. We demonstrate that magneto-ionic devices can perform as synaptic elements with dynamically tunable depression linearity controlled by an external magnetic field, a functionality reminiscent of neuromodulation in biological systems.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!