Group of Nanomagnetism and Magnetization Processes

On 28^th and 29^th we hold the kickoff meeting of the iLINK0052 project on “Nanorobots and Magnetic sensors based on Nanowires”. This enriching and discussion full meeting was attended by Dr. Olga Kazakova (NPL, Teddington, UK), Ass. Prof. Jürgen Kosel (KAUST, Saudi Arabia), Ass. Prof. Dieter Suess (University of Vienna), Dr. Xiangzhong Chen (ETH, Zurich), Dr. Christoph Vogler (University of Vienna) apart from staff members of ICMM/CSIC Manuel Vazquez, Agustina Asenjo, Oksana Chubykalo-Fesenko, Cristina Bran, Rafael Perez, David Navas, Alfredo Jacas, and Prof. Laura H. Lewis from Northeastern University, Boston.

The traditional summer excursion of the group took place June 26th to visit Sigüenza, the old Castilian city which origin goes back to the Celtiberian Segontia. After the 2 hours walk by the pines and under a suffocating sun to the nearby Natural Park, we had a comforting lunch. It was followed by the cultural visit to the medieval Castle and the gothic Cathedral that hosts the famous tomb of the Doncel.

“Geometrically designed domain wall trap in tri-segmented nickel magnetic nanowires for spintronics devices”

  Farzad Nasirpouri, Seyed-Majid Peighambari-Sattari, Cristina Bran, Ester M. Palmero, Eider Berganza Eguiarte, Manuel Vazquez, Aristotelis Patsopoulos and Dimitris Kechrakos, Scientific Reports  (2019) 9:9010 | https://doi.org/10.1038/s41598-019-45553-w

 

“Domain wall traps” have been engineered diameter-modulated (DM) cylindrical magnetic nanowires (NWs). A systematic study on the magnetization behavior, domain wall structure and its nucleation/propagation in tri-segmented diameter-modulated Ni nanowires was performed to investigate the magnetization reversal as function of segment geometry. Two distinct geometries include: dumbbell-type (type I) and rolling pin-type (type II). Based on experimental and theoretical simulations, it was evidenced that the wide-narrow junctions create trap sites for domain walls where the narrow segment restricts their motion. This type of geometrically engineered nanowires exhibit potential efficiency for future novel spintronic devices in particular when assembled in arrays as a practical 2D memory devices.

The European Union patent EP19382510 has been filed with the title “Method for nanostructured materials fabrication combining soft lithographic imprint, aluminium anodization and metal sputtering” by Manuel Vazquez (ICMM/CSIC), David Gonzalez (ICMM/CSIC) and David Navas (Porto University).

Jose Angel Fernandez Roldán defended his work entitled “Micromagnetism of cylindrical nanowires with compositional and geometric modulations” supervised by Dr. Rafael Perez del Real and Dr. Oksana Chubykalo-Fesenko, and the scientific advice of Prof. Manuel Vazquez, to become Doctor in Physics by the Autonomous University of Madrid. The defense was taken in June 3^rd, and the work received the maximum qualification of Sobresaliente-cum laude by unanimous decision of the Doctoral Commission.

Since 1st of June Dr. David Navas Otero has joined the group after he was awarded with a  Ramón y Cajal contract.

The group has been awarded with two i-LINK projects supported by CSIC for the period 2019-2020:

i-LINKA20052  “Nanorobots and sensors based on magnetic nanowires”

Coordinated by Manuel Vázquez, and partners from Institute of Robotics and Intelligent Systems at ETH, Zurich (Dr. S. Pané), Sensing, Magnetism and Microsystems group at KAUST, Thuwal, Saudi Arabia (Ass. Prof. J. Kosel), Functional Materials group at University of Vienna (Dr. Ch. Vogler), Nanomagnetism team of Quantum Detection Group at National Physical Laboratory NPL; Teddington, UK (Dr. O. Kazakova) and SuessCo  Sensors GmbH, Herzogenburg, Austria (Eng. R. Windl).

 

i-LINKA20074 “Towards a personalized medicine: a proof of concept”

Coordinated by Rafael Pérez, and partners from Nanomagnetism Laboratory at University of Northeastern, Boston, EEUU (Prof. Laura H. Lewis),  Laboratory of Nanosensors for Chemical Imaging of Living Systems at University of Northeastern, Boston, EEUU (Prof. Heather Clark) and the Department of Chemical Engineering at University of Monash, Australia (Dr. Simon Corrie).

Prof. Laura H. Lewis is visiting us again under the auspices of the program supported by Fulbright España from May to August 2019. Laura is the Distinguished University and Cabot Professor of Chemical Engineering, and Professor of Mechanical and Industrial Engineering at Northeastern University in Boston, MA, U.S.A. Her current collaborative research with our group is focusing on “advanced applications of amorphous magnetic microwires”.

«3D arrays of magnetic nanowires” by Dr. Yuri Ivanov from the Material Science and Metallurgy Department, University of Cambridge, May 16th .

NanoResearch

Stepwise magnetization reversal of geometrically tuned in diameter Ni and FeCo bi-segmented nanowire arrays

Ester M. Palmero, Miguel Méndez, Silvia González, Cristina Bran, Víctor Vega, Manuel Vázquez and Víctor M. Prida

https://doi.org/10.1007/s12274-019-2385-9

The magnetization process of hexagonal dense arrays of bi-segmented Ni and FeCo nanowires consisting of two well defined diameters (45 and 80 nm) are reported. The nanowires were grown inside of tailored pores of anodic alumina templates by combined anodization, atomic layer deposition (ALD) and electrodeposition. The results clearly enable to identify a two-step process ascribed to the respective segments of different diameter, as concluded from the differential susceptibility of the loops, and confirmed by the first-order reversal curve (FORC) distribution diagrams, where an elongation parallel to the interaction axis around two coercive field values is obtained. This well-defined two-step magnetization reversal process through the nanowire diameter design represents a promising route for the advanced control of the remagnetization in arrays of magnetic multidomain systems.

This study performed in collaboration with the University of Oviedo has been supported by the Spanish Ministerio de Economia y Competitividad (MINECO) under the coordinated research Projects MAT2013-48054-C2 and MAT2016-76824-C3.