Magnetic materials research and development.
Universidad de Oviedo.

The investigation group specializes on the obtention of based Fe alloys by melt spinning technique: Finemet type and Fe-Al and Fe-Ga. These last ones present high magnetostriction and are ideal for the design and fabrication of sensors for the measurement of torques in the boats’ tail axis. These alloys have been magnetically characterized and their saturation magnetrostriction has been determined. In addition, their stability has been tested by subjecting them to extreme oxidation treatments.

Recently, we have oriented our investigation to the magnetic characterization of magnetic monolayer nanowire arrays, useful in circulator devices and insulators that work in the microwave range, and of multilayer nanowires and films, which work as giant magnetoresistance sensors.

The magnetic behavior of multilayer nanowires highly depends on the ferromagnetic material type and on their geometric characteristics such as diameter, length, thickness, distance between layers and nanowires.

Aiming to obtain insight on the magnetization distributions and the hysteretical properties of these nanostructures, we have used the micromagnetic simulation software Nmag. Micromagnetic simulations are useful, where analytical calculations are too complex or experimental measurements are not available.

On the other hand, in the past few years, nanostructures based on the GMR effect as in spin valves, have become essential parts in different sensors used for the detection or recognition of biomolecules. In these biosensors, the micro/nanomagnetic particles are use as biomolecular markers and the GMR elements detect the presence of the particles immobilized in the sensor due to intermolecular interactions.

In the present research project, using OOMMF software, giant magnetoresistance sensors and spin valves are being simulated to detect magnetic nanoparticles used as markers, to determine quickly and accurately free and total PSA.

Personnel

• Researchers: Laura Elbaile, Mª Rosario Díaz

Research lines:

• Specialized in the obtaining of Finement type based Fe alloys and Fe-Al and Fe-Ga alloys by using the ultra-fast cooling method.

Infrastructure:

• Melt spinner HV (Bühler) to produce amorphous or microcrystalline ribbons.
• Fabrication of nanoporous membranes and nanowire arrays.
• Electromagnet (2,7 T).
• Experimental device for measuring surface hysteresis loops.
• Vibrating sample magnetometer.
• X-ray diffractometer.
• Scanning electron microscope SEM with EDX analysis.
• Transmission electron microscope TEM.

Research projects:

• "Magnetostriction improvement in Fe-Al and Fe-Ga alloys obtained by melt spinning technique for application in magnetic sensors", MICINN Ref. MAT 2008-06784/MAT (2009-2012).
• "Detection of immunogenic markers (NKG2DL)in tumor cells labeled by magnetic nanoparticles.",FiCyt IB09-128 (2009-2010).
• "Detection of free and total PSA using magnetic methods", University of Oviedo Ref: SV-PA-13-ECOEMP-34 (from 04/2013 to 12/2013).

Selection of recent publications (in the last years):

• "Magnetostatic interaction in Fe-Co nanowires" L. Elbaile, R. D. Crespo, V. Vega and J. A. García. J. of Nanomaterials, ID 198453 (2012)
• "Magnetic behavior in arrays of Ni79Fe21 and Ni79Fe21/Cu nanowires" L. Elbaile, I. G. Cubero, R. D. Crespo, V. Vega and J. A. García. J. Alloy Compd. 536S, S359 (2012)
• "Magnetic characterization of Fe-Al-B amorphous ribbons obtained by the melt spinning technique". J.A. García, J. Carrizo, L. Elbaile, M. Rivas, R.D. Crespo, and J.C. Martínez-García. European Phys. J.15, 03003 (2011)
• "Surface and bulk magnetic properties of amorphous and nanocrystalline Ni-substituted Finemet samples". L. Elbaile, R.D. Crespo, A.R. Pierna and J.A. García. J. Non-Cryst. Solids 354, 47 (2008).
• "Effect of the dipolar field on the surface magnetic properties in Co-based amorphous ribbons". L. Elbaile, R. D. Crespo, M. Tejedor and J. A. García. Sensor Lett. 5, 1 (2007).

Notable collaborations:

• Spain: Universidad de Santiago de Compostela (José Rivas Rey). UPV/EHU (Ángel R. Pierna), UPV/EHU (G. Kurlyandskaya), Oviedo (R. Iglesias), UB Barcelona (Enric Bertran)