Graduate Program in Spintronics Seminar“Controlling magnetism byinterface engineering”
Dr. Liza Herrera DIEZ
C2N: CENTRE FOR NANOSCIENCE AND
NANOTECHNOLOGYCNRS- UNIVERSITÉ PARIS SUD –UNIVERSITÉ PARIS SACLAYTime : 2:00pm-3:30pm
Date : Friday,

June 7, 2019

Venue: Seminar Room 2 :407
Education and Research Building,Materials Science and Materials Processing,
Graduate School of Engineering

Contact to : Makoto Kohda(makoto［at］material.tohoku.ac.jp)

Controlling magnetism by interface engineering
L. Herrera Diez
Centre for Nanoscience and Nanotechnology, CNRS - Université Paris Sud. Palaiseau, France.

Reliable control of magnetic anisotropy and domain wall motion in technologically relevant magnetic materials is at the heart of a variety of emerging practical applications in spintronics. In
particular, modulating the velocity of a magnetic domain wall and constraining its motion at predefined positions is a key aspect in the development of novel magnetic devices in view of applications
ranging from magnetic sensors to magnetic memories.
In this seminar I will present our recent results on domain wall motion control by tuning theperpendicular magnetic anisotropy (PMA) and the Dzyaloshinskii Moriya interaction (DMI) usingelectric (E) fields [1,2] and He+ ion irradiation [3,4] in Ta/CoFeB/MgO and Pt/Co/HfO2 layers.
The impact of the modulation of PMA and DMI is observed in magnetic domain wall motion in thecreep regime and beyond. I will discuss how this is intimately related to the structural/electronic
characteristics of the magnetic thin film interfaces; which underlines the critical importance of interface engineering in the design of high performing spintronics devices.
[1] L. Herrera Diez et. al. ‘Non-volatile ionic modification of the Dzyaloshinskii Moriya Interaction’
Under review 2019.
[2] Y. Liu et. al., ‘Electric field controlled domain wall dynamics and magnetic easy axis switchingin liquid gated CoFeB/MgO films’ J. Appl. Phys. 122, 133907 (2017).
[3] L. Herrera Diez. et. al., ‘Enhancement of Dzyaloshinskii-Moriya interaction and domain wall
velocity through interface intermixing in Ta/CoFeB/MgO’ Physical Review B 99, 054431 (2019).
[4] L. Herrera Diez et. al., ‘Controlling magnetic domain wall motion in the creep regime in He+irradiated CoFeB/MgO films with perpendicular anisotropy’ Appl. Phys. Lett. 107, 032401 (2015).
Liza Herrera Diez has an interdisciplinary background in physics and chemistry. She studied
physical chemistry at the National University of Cordoba (Argentina) and conducted her doctoral
studies at the Max-Planck Institute for Solid State Research while enrolled in the physics doctoral
school at École Polytechnique Fédérale de Lausanne (2008-2010). During this time she performed
studies on magnetic domain wall dynamics and magneto-transport in devices based on diluted
ferromagnetic semiconductors. From 2011 to 2012 she worked as a postdoctoral researcher atInstitut Néel in Grenoble. During this postdoctoral stay she worked on electric field control ofmagnetic anisotropy and domain wall dynamics in ferromagnetic field-effect transistor devices.
Since 2013 she is a CNRS researcher at C2N and her main scientific interests are oriented towards
the control of domain wall dynamics in multifunctional nanodevices.