Epitaxial growth and characterization of the heusler alloy Mn3Ge for future use in magnetic tunnel junctions
(2019) PHYM01 20161Solid State Physics
Department of Physics
- Abstract
- To allow further device scalability within the data storage industry there needs to be continued research of new technologies. One promising technology is the Magnetic Random Access Memory (MRAM), based on magnetoresistive elements, which is non-volatile; consume low power and have fast read and write operations. To make the technology scalable, the bit (the smallest element in the MRAM) needs to be stable of thermal fluctuations and switch efficiently. The bit is a Magnetic Tunnel Junction (MTJ) which is amongst one of the simplest spintronic devices. It consists of two ferromagnetic layers: one bottom layer with pinned magnetism and one top layer which is free and can switch its magnetic polarity. Between the two magnets, there is a... (More)
- To allow further device scalability within the data storage industry there needs to be continued research of new technologies. One promising technology is the Magnetic Random Access Memory (MRAM), based on magnetoresistive elements, which is non-volatile; consume low power and have fast read and write operations. To make the technology scalable, the bit (the smallest element in the MRAM) needs to be stable of thermal fluctuations and switch efficiently. The bit is a Magnetic Tunnel Junction (MTJ) which is amongst one of the simplest spintronic devices. It consists of two ferromagnetic layers: one bottom layer with pinned magnetism and one top layer which is free and can switch its magnetic polarity. Between the two magnets, there is a tunnel barrier of 1-2 nm thickness where the majority and minority spin electrons can tunnel through. To enable future downscaling of the MTJ while improving storage capacity in MRAMs, one need to utilize ferromagnetic materials that are known for having perpendicular magnetic anisotropy and high spin polarization. One material with the mentioned properties is the tetragonal structure of D022-Mn3Ge, where D022 is a type of crystal structure and Mn3Ge is an alloy between Manganese and Germanium. Thin films were grown using molecular beam epitaxy which, when characterized, were found to have a high perpendicular magnetic anisotropy. One problem with the films were island formations due to a surface energy mismatch between the substrate and the thin film. The surface roughness needs further improvement as the surface must be atomically flat. Otherwise it would easily cause pinholes in the thin tunnel barrier. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8986244
- author
- Andreasson, Amanda LU
- supervisor
- organization
- course
- PHYM01 20161
- year
- 2019
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 8986244
- date added to LUP
- 2019-06-20 10:52:37
- date last changed
- 2019-06-20 10:52:37
@misc{8986244, abstract = {{To allow further device scalability within the data storage industry there needs to be continued research of new technologies. One promising technology is the Magnetic Random Access Memory (MRAM), based on magnetoresistive elements, which is non-volatile; consume low power and have fast read and write operations. To make the technology scalable, the bit (the smallest element in the MRAM) needs to be stable of thermal fluctuations and switch efficiently. The bit is a Magnetic Tunnel Junction (MTJ) which is amongst one of the simplest spintronic devices. It consists of two ferromagnetic layers: one bottom layer with pinned magnetism and one top layer which is free and can switch its magnetic polarity. Between the two magnets, there is a tunnel barrier of 1-2 nm thickness where the majority and minority spin electrons can tunnel through. To enable future downscaling of the MTJ while improving storage capacity in MRAMs, one need to utilize ferromagnetic materials that are known for having perpendicular magnetic anisotropy and high spin polarization. One material with the mentioned properties is the tetragonal structure of D022-Mn3Ge, where D022 is a type of crystal structure and Mn3Ge is an alloy between Manganese and Germanium. Thin films were grown using molecular beam epitaxy which, when characterized, were found to have a high perpendicular magnetic anisotropy. One problem with the films were island formations due to a surface energy mismatch between the substrate and the thin film. The surface roughness needs further improvement as the surface must be atomically flat. Otherwise it would easily cause pinholes in the thin tunnel barrier.}}, author = {{Andreasson, Amanda}}, language = {{eng}}, note = {{Student Paper}}, title = {{Epitaxial growth and characterization of the heusler alloy Mn3Ge for future use in magnetic tunnel junctions}}, year = {{2019}}, }