Electric Field-Controlled Magnetic
Anisotropy in Magnetic
Nanoheterostructures
A. M. Korostil and M. M. Krupa
1 Introduction
Bilayers containing an interface between a thin layer of a heavy metal and a magnetic
one are important hybrid materials in spintronics, as they combine magnetic order,
strong spin–orbit interaction, and broken inversion symmetry. This together with
exchange interactions of the magnetic layer can lead to perpendicular magnetic
anisotropy (PMA) [1], Dzyaloshinskii–Moriya interactions [2, 3], spin–orbit torques,
Rashba–Edelstein effects, and more [4]. Spin–orbit interactions near the interface
provide a handle to alter these properties by tuning chemical composition, interface
structure, or gate voltages, as demonstrated most extensively for magnetic anisotropy
[5, 6].
Magnetic anisotropy energy (MAE) refers to the dependence of the total energy
of a magnetic system on the real-space orientation of its magnetization. The MAE
is responsible for the orientational stability of magnetic domains, and hence lies at
the heart of both magnetic hard disk drives and magnetic random access memories.
There are two main contributions to the MAE: the magnetocrystalline anisotropy
which arises from electronic spin–orbit interactions, and shape anisotropy which
arises from the magnetostatic dipolar interaction. For a thin ferromagnetic film, the
magnetostatic energy is minimized when the magnetization is in the plane of the
film, leading to in-plane magnetic anisotropy (IMA).
To stabilize perpendicular magnetic anisotropy (PMA), the magnetocrystalline
anisotropy energy must overcome the shape anisotropy. From the technological point
of view, PMA is very important, since it enables an increased bit storage density,
through a reduced size of the magnetic domains that store each bit of information.
Solving this problem involves description of the magnetocrystalline anisotropy of
A. M. Korostil (B) · M. M. Krupa
Institute of Magnetism (IMAG) NASU and MESU, Kiev, Ukraine
e-mail: korostilandrii@gmail.com
© Springer Nature Switzerland AG 2021
O. Fesenko and L. Yatsenko (eds.), Nanomaterials and Nanocomposites,
Nanostructure Surfaces, and Their Applications, Springer Proceedings
in Physics 246, https://doi.org/10.1007/978-3-030-51905-6_2
9
Anisotropy in Magnetic
Nanoheterostructures
A. M. Korostil and M. M. Krupa
1 Introduction
Bilayers containing an interface between a thin layer of a heavy metal and a magnetic
one are important hybrid materials in spintronics, as they combine magnetic order,
strong spin–orbit interaction, and broken inversion symmetry. This together with
exchange interactions of the magnetic layer can lead to perpendicular magnetic
anisotropy (PMA) [1], Dzyaloshinskii–Moriya interactions [2, 3], spin–orbit torques,
Rashba–Edelstein effects, and more [4]. Spin–orbit interactions near the interface
provide a handle to alter these properties by tuning chemical composition, interface
structure, or gate voltages, as demonstrated most extensively for magnetic anisotropy
[5, 6].
Magnetic anisotropy energy (MAE) refers to the dependence of the total energy
of a magnetic system on the real-space orientation of its magnetization. The MAE
is responsible for the orientational stability of magnetic domains, and hence lies at
the heart of both magnetic hard disk drives and magnetic random access memories.
There are two main contributions to the MAE: the magnetocrystalline anisotropy
which arises from electronic spin–orbit interactions, and shape anisotropy which
arises from the magnetostatic dipolar interaction. For a thin ferromagnetic film, the
magnetostatic energy is minimized when the magnetization is in the plane of the
film, leading to in-plane magnetic anisotropy (IMA).
To stabilize perpendicular magnetic anisotropy (PMA), the magnetocrystalline
anisotropy energy must overcome the shape anisotropy. From the technological point
of view, PMA is very important, since it enables an increased bit storage density,
through a reduced size of the magnetic domains that store each bit of information.
Solving this problem involves description of the magnetocrystalline anisotropy of
A. M. Korostil (B) · M. M. Krupa
Institute of Magnetism (IMAG) NASU and MESU, Kiev, Ukraine
e-mail: korostilandrii@gmail.com
© Springer Nature Switzerland AG 2021
O. Fesenko and L. Yatsenko (eds.), Nanomaterials and Nanocomposites,
Nanostructure Surfaces, and Their Applications, Springer Proceedings
in Physics 246, https://doi.org/10.1007/978-3-030-51905-6_2
9