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Mater Sci Nanotechnol 2017
Volume 1 Issue 3
Magnetic Materials 2017
October 09-10, 2017 London, UK
International Conference on
Kaiyou Wang, Materials Science and Nanotechnology
Control ferromagnets at room temperature
without external magnetic field
E
lectrically controlling the spin in solids is the core
of spintronics. We investigated that Spin Hall effect
controls the magnetization switching in heavy metal/
ferromagnet/heavy metal multilayers and also piezo
voltages control the magnetization switching of Heusler
alloy CoFeAl. By designing the device structure, we
demonstrate a strong damping-like torque from the
Spin Hall effect and unmeasurable field-like torque
from Rashba effect. The spin-orbit effective fields due
to the Spin Hall effect were investigated quantitatively
and were found to be consistent with the switching
effective fields after accounting for the switching current
reduction due to thermal fluctuations from the current
pulse. The spin-orbit torque switching controllably
in above structures have to have the assistant of
the external magnetic field. Without breaking the
symmetry of the structure of the thin film, we realize
the deterministic magnetization switching in a hybrid
ferromagnetic/ferroelectric structure with Pt/Co/Ni/Co/
Pt layers on PMN-PT substrate. The effective magnetic
field can be reversed by changing the direction of the
applied electric field on the PMN-PT substrate, which
fully replaces the controllability function of the external
magnetic field. We also investigated the planar Hall
effect devices based on the tunability of the planar Hall
resistance in ferromagnetic Co
2
FeAl devices solely by
piezo voltages. The room temperature magnetic NOT
and NOR gates have been demonstrated based on
the Co
2
FeAl planar Hall effect devices without external
magnetic field.
Biography
Kaiyou Wang, PhD, Professor in Institute of Semiconductors in Chinese
Academy of Sciences, Deputy Director of State Key Laboratory for Superlattices
& Microstructure, obtained his PhD in 2005 at School of Physics & Astronomy,
University of Nottingham. He worked as a Researcher Assistant from March to the
end of May/2005 in University of Nottingham. He then worked as a Researcher in
Hitachi Cambridge Laboratory from June/2005 to the end of March/2009. During
his stay in UK, he had twice short visits to Institute of Physics, Poland and also a
short visit to Niels Bohr Institute, Copenhagen. He joined State Key Laboratory for
Superlattices & Microstructure, Institute of Semiconductors in CAS as a member
of “100 Talent Program”. In 2012, he has been awarded the “National Outstanding
Youth Foundation” from NSFC. In 2014, he was selected to be excellent in the
“100 Talent Program” final assessment. His current research interests include:
(1) spintronic devices; (2) physical properties based on low dimensional nano-
electronic devices.
kywang@semi.ac.cnKaiyou Wang
Institute of Semiconductors, CAS, PR China