Staff directory

Enric Menéndez Dalmau

Visiting Senior Researcher
Universitat Autònoma de Barcelona
Magnetic Nanostructures



  • Lateral Magnetically Modulated Multilayers by Combining Ion Implantation and Lithography

    Menéndez E., Modarresi H., Petermann C., Nogués J., Domingo N., Liu H., Kirby B.J., Mohd A.S., Salhi Z., Babcock E., Mattauch S., Van Haesendonck C., Vantomme A., Temst K. Small; 13 (11, 1603465) 2017. 10.1002/smll.201603465.

    The combination of lithography and ion implantation is demonstrated to be a suitable method to prepare lateral multilayers. A laterally, compositionally, and magnetically modulated microscale pattern consisting of alternating Co (1.6 µm wide) and Co-CoO (2.4 µm wide) lines has been obtained by oxygen ion implantation into a lithographically masked Au-sandwiched Co thin film. Magnetoresistance along the lines (i.e., current and applied magnetic field are parallel to the lines) reveals an effective positive giant magnetoresistance (GMR) behavior at room temperature. Conversely, anisotropic magnetoresistance and GMR contributions are distinguished at low temperature (i.e., 10 K) since the O-implanted areas become exchange coupled. This planar GMR is principally ascribed to the spatial modulation of coercivity in a spring-magnet-type configuration, which results in 180° Néel extrinsic domain walls at the Co/Co-CoO interfaces. The versatility, in terms of pattern size, morphology, and composition adjustment, of this method offers a unique route to fabricate planar systems for, among others, spintronic research and applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  • Voltage-Induced Coercivity Reduction in Nanoporous Alloy Films: A Boost toward Energy-Efficient Magnetic Actuation

    Quintana A., Zhang J., Isarain-Chávez E., Menéndez E., Cuadrado R., Robles R., Baró M.D., Guerrero M., Pané S., Nelson B.J., Müller C.M., Ordejón P., Nogués J., Pellicer E., Sort J. Advanced Functional Materials; 2017. 10.1002/adfm.201701904.

    Magnetic data storage and magnetically actuated devices are conventionally controlled by magnetic fields generated using electric currents. This involves significant power dissipation by Joule heating effect. To optimize energy efficiency, manipulation of magnetic information with lower magnetic fields (i.e., lower electric currents) is desirable. This can be accomplished by reducing the coercivity of the actuated material. Here, a drastic reduction of coercivity is observed at room temperature in thick (≈600 nm), nanoporous, electrodeposited Cu-Ni films by simply subjecting them to the action of an electric field. The effect is due to voltage-induced changes in the magnetic anisotropy. The large surface-area-to-volume ratio and the ultranarrow pore walls of the system allow the whole film, and not only the topmost surface, to effectively contribute to the observed magnetoelectric effect. This waives the stringent "ultrathin-film requirement" from previous studies, where small voltage-driven coercivity variations were reported. This observation expands the already wide range of applications of nanoporous materials (hitherto in areas like energy storage or catalysis) and it opens new paradigms in the fields of spintronics, computation, and magnetic actuation in general. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


  • Interdependence between training and magnetization reversal in granular Co-CoO exchange bias systems

    Menendez E.; Dias T.; Geshev J.; Lopez-Barbera J.F.; Nogues J.; Steitz R.; Kirby B.J.; Borchers J.A.; Pereira L.M.C.; Vantomme A.; Temst K. Physical Review B - Condensed Matter and Materials Physics; 2014. 10.1103/PhysRevB.89.144407. IF: 3.664