Group of Nanomagnetism and Magnetization Processes
Instituto de Ciencia de Materiales de Madrid, CSIC
Prof. Manuel Vazquez
The IEEE Magnetics Society Distinguished Service Award is established to honor outstanding service to the Magnetics Society
Prof. Manuel Vazquez from the Institute of Materials Science of Madrid, CSIC, has been granted the 2021 Distinguished Service Award.
The citation reads: For tremendously strengthening the IEEE Magnetics Society outreach worldwide and dedicated efforts to engage new people in service to the society
Magnetic Configurations in Modulated Cylindrical Nanowires
Cristina Bran, Jose Angel Fernandez-Roldan, Rafael P. del Real, Agustina Asenjo, Oksana Chubykalo-Fesenko and Manuel Vazquez
Nanomaterials 2021, 11, 600
DOI: doi.org/10.3390/nano11030600
Cylindrical magnetic nanowires show great potential for 3D applications such as magnetic recording, shift registers, and logic gates, as well as in sensing architectures or biomedicine. Their cylindrical geometry leads to interesting properties of the local domain structure, leading to multifunctional responses to magnetic fields and electric currents, mechanical stresses, or thermal gradients. This review article summarizes the work carried out in our group on the fabrication and magnetic characterization of cylindrical magnetic nanowires with modulated geometry and anisotropy. The nanowires are prepared by electrochemical methods with precise control over geometry, morphology, and composition. Different routes to control the magnetization configuration and its dynamics through the geometry and magnetocrystalline anisotropy are presented. The diameter modulations change the typical single domain state present in cubic nanowires, providing the possibility to confine or pin circular domains or domain walls in each segment. The control and stabilization of domains and domain walls in cylindrical wires has been achieved in multisegmented structures by alternating magnetic segments of different magnetic properties or with non-magnetic layers.
This article reviews the most significant investigations carried out by the GNMP group on cylindrical magnetic nanowires with modulated geometry and anisotropy. Such modulations promote the occurrence of stable magneto-chiral structures and provide further information for the design of cylindrical nanowires for multiple applications.
Magnetoelectric Polymer-Based Nanocomposites with Magnetically Controlled Antimicrobial Activity
Margarida M. Fernandes, Pedro Martins, Daniela M. Correia, Estela O. Carvalho, Francisco M. Gama, Manuel Vazquez, Cristina Bran and Senentxu Lanceros-Mendez
ACS Appl. Bio Mater. 2021, 4, 1, 559–570
DOI: doi.org10.1021acsbm.0c01125
The emergence of antimicrobial resistance is considered a public health problem due to the overuse and misuse of antibiotics which are losing efficacy toward an increasing number of microorganisms. Advanced antimicrobial strategies via development of alternative drugs and materials able to control microbial infections, especially in clinical settings, are urgently needed. In this work, nanocomposite films were developed from piezoelectric PVDF polymer filled with nickel nanowires to control and enhance the antimicrobial activity via the application of a magnetic stimulus. The material was achieved through crystallization of PVDF upon incorporation of anisotropic and negatively charged Ni nanowires in the polymeric matrix. The nanocomposites have shown to possess antimicrobial properties which was considerably boosted through the application of a magnetic field. More than 55% of bacterial growth inhibition was obtained by employing controlled dynamic magnetic conditions compared to only 25% inhibition obtained under static conditions. This work demonstrates a proof-of-concept for materials able to boost on demand their antimicrobial activity and opens the room for applications in novel medical devices with improved control of healthcare-associated infections.
This work has been performed in collaboration between the GNMP group at ICMM/CSIC and the University of Braga in Portugal profiting of their respective expertise in magnetic nanowires and polymers for biomedical applications.
Cylindrical Magnetic Nanowires Applications
Julián A. Moreno, Cristina Bran, Manuel Vazquez and Jürgen Kosel
IEEE Transactions on Magnetics
DOI: 10.1109/TMAG.2021.3055338
Cylindrical magnetic nanowires feature unique properties, which make them attractive particularly for novel applications. These one-dimensional structures introduce a pronounced shape anisotropy that together with material selection can strongly affect the magnetic properties and can be tuned by incorporating segments of different materials or diameters along the length. They attract a large interest in the scientific community, ranging from physicists to material scientists to bioengineers. These nanowires are developed for and employed in very diverse applications in medicine, biology, data and energy storage, catalysis or microwave electronics, among others. In this review, most active emerging applications of cylindrical nanowires are overviewed. Advantages include several key features as low-cost and high level of control over the design. A fundamental property that distinguishes those applications is the operating frequency that can be chosen to apply as an underlying structure in this review. We attempt to provide a wide and organized view of applications based on cylindrical magnetic nanowires with a focus on tailored physical and chemical properties.
This Review Article is a collaboration between the groups at KAUST, Thuwal, Saudi Arabia and GNMP at ICMM/CSIC. It was supported by the Spanish Ministry MINECO, under project MAT2016-76824-C3-1-R, the Regional Government of Madrid under project S2018/NMT-4321 NANOMAGCOST-CM, and CSIC under project iLinkA20052.