ATOMs ‐ Atomistic to Micromagnetic modelling: from permanent magnets to magnetic hybrid materials
In our research we show that the combination of atomistic and micromagnetic simulations in connection with TEM and synchrotron measurements can give a better understanding
of the morphological and chemical composition of magnetic and metallic hybrid materials [1,2]. The problem of interface and grain boundaries and its changes in intrinsic properties are rooted in structural defects of crystal structures and influence effects like intrinsic magnetic properties and interface phenomena like spin scattering. We discuss these effects and its influence on permanent magnets used in hybrid cars, over novel magnetic hybrid structures to artificial spin ice structures. Anisotropic sintered NdFeB magnets consist of polyhedral grains, which have a distribution of size and shape, separated by a grain boundary phase with various compositions. Such magnets are sensitive to the crystallographic structure near grain boundaries and interfaces, and this considerably influences the magnetic properties that can be understood and quantified with solid‐state molecular dynamics. It is shown that change in local properties can be linked to the strain/stress effects on the atomistic scale. Such interface and coupling effects also play an important role in magnetic hybrid as well as in artificial spin ice structures. Where it was found that heterogeneous nanostructures of Co/Pd and permalloy multilayers exhibit mutual domain imprinting that support either a pure closure-‐domain pattern, a mixed Landau‐maze domain state or a perpendicular exchange-‐spring magnetization structure and in artificial spin ice systems where geometrical manipulation of arrays can induce chirality. Control over such hybrid and spin ice structures could lead to the development of a wide range of technologies, from multilayer data storage media and radio‐frequency nano‐oscillators [3] to encryption applications[4].
References:
[1] G. Hrkac, T. Woodcock, et al, Applied Physics Letters 97, 2010, 232511
[2] T. Woodcock, Y. Zhang, G. Hrkac et al. Scripta Materialia, Volume 67, Issue 6, 2012, Pages 536–541
[3] P. Wohlhütter, M. Bryan et.al. Nature Communications 6, 7836 (2015)
[4] S. Gliga, G. Hrkac et al. Nature Materials 16, 1106–1111 (2017)
Date and Time
Location
Hosts
Registration
- Date: 20 Sep 2019
- Time: 11:00 AM to 12:15 PM
- All times are (UTC-06:00) Mountain Time (US & Canada)
-
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- 1420 Austin Bluffs Pkwy
- Colorado Springs, Colorado
- United States 80918
- Building: Osborne
- Room Number: A204
- Contact Event Host
-
Zbigniew Celinski
DEpartment of Physics
UCCS
- Co-sponsored by UCCS
Speakers
Gino Hrkac of University of Exeter
ATOMs ‐ Atomistic to Micromagnetic modelling: from permanent magnets to magnetic hybrid materials
In our research we show that the combination of atomistic and micromagnetic simulations in connection with TEM and synchrotron measurements can give a better understanding
of the morphological and chemical composition of magnetic and metallic hybrid materials [1,2]. The problem of interface and grain boundaries and its changes in intrinsic properties are rooted in structural defects of crystal structures and influence effects like intrinsic magnetic properties and interface phenomena like spin scattering. We discuss these effects and its influence on permanent magnets used in hybrid cars, over novel magnetic hybrid structures to artificial spin ice structures. Anisotropic sintered NdFeB magnets consist of polyhedral grains, which have a distribution of size and shape, separated by a grain boundary phase with various compositions. Such magnets are sensitive to the crystallographic structure near grain boundaries and interfaces, and this considerably influences the magnetic properties that can be understood and quantified with solid‐state molecular dynamics. It is shown that change in local properties can be linked to the strain/stress effects on the atomistic scale. Such interface and coupling effects also play an important role in magnetic hybrid as well as in artificial spin ice structures. Where it was found that heterogeneous nanostructures of Co/Pd and permalloy multilayers exhibit mutual domain imprinting that support either a pure closure-‐domain pattern, a mixed Landau‐maze domain state or a perpendicular exchange-‐spring magnetization structure and in artificial spin ice systems where geometrical manipulation of arrays can induce chirality. Control over such hybrid and spin ice structures could lead to the development of a wide range of technologies, from multilayer data storage media and radio‐frequency nano‐oscillators [3] to encryption applications[4].
References:
[1] G. Hrkac, T. Woodcock, et al, Applied Physics Letters 97, 2010, 232511
[2] T. Woodcock, Y. Zhang, G. Hrkac et al. Scripta Materialia, Volume 67, Issue 6, 2012, Pages 536–54
[3] P. Wohlhütter, M. Bryan et.al. Nature Communications 6, 7836 (2015)
[4] S. Gliga, G. Hrkac et al. Nature Materials 16, 1106–1111 (2017)
Email:
Address:College of Engineering, Mathematics and Physical Sciences, Harrison Building, Exeter, England, United Kingdom, EX4 4QF