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Biased magnetic materials in RAM applications

Ramprecht, Jörgen and Sjöberg, Daniel LU (2007) In Technical Report LUTEDX/(TEAT-7155)/1-29/(2007) TEAT-7155.
Abstract
The magnetization of a ferro- or ferri-magnetic material has been

modeled with the Landau-Lifshitz-Gilbert (LLG) equation. In this

model demagnetization effects are included. By applying a linearized

small signal model of the LLG equation, it was found that the

material can be described by an effective permeability and with the

aid of a static external biasing field, the material can be switched

between a Lorentz-like material and a material that exhibits a

magnetic conductivity. Furthermore, the reflection coefficient for

normally impinging waves on a PEC covered with a

ferro/ferri-magnetic material, biased in the normal direction, is

... (More)
The magnetization of a ferro- or ferri-magnetic material has been

modeled with the Landau-Lifshitz-Gilbert (LLG) equation. In this

model demagnetization effects are included. By applying a linearized

small signal model of the LLG equation, it was found that the

material can be described by an effective permeability and with the

aid of a static external biasing field, the material can be switched

between a Lorentz-like material and a material that exhibits a

magnetic conductivity. Furthermore, the reflection coefficient for

normally impinging waves on a PEC covered with a

ferro/ferri-magnetic material, biased in the normal direction, is

calculated. When the material is switched into the resonance mode,

we found that there will be two distinct resonance frequencies in

the reflection coefficient, one associated with the precession

frequency of the magnetization and one associated with the thickness

of the layer. The former of these resonance frequencies can be

controlled by the bias field and for a bias field strength close to

the saturation magnetization, where the material starts to exhibit a

magnetic conductivity, one can achieve low reflection (around -20

dB) for a quite large bandwidth (more than two decades). (Less)
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author
organization
publishing date
type
Book/Report
publication status
published
subject
in
Technical Report LUTEDX/(TEAT-7155)/1-29/(2007)
volume
TEAT-7155
pages
29 pages
publisher
[Publisher information missing]
external identifiers
  • scopus:34547246315
language
English
LU publication?
yes
id
2b66608f-1e0d-4aaf-9fab-0955d8477c35 (old id 1788117)
date added to LUP
2011-02-21 09:26:45
date last changed
2017-01-01 08:15:12
@techreport{2b66608f-1e0d-4aaf-9fab-0955d8477c35,
  abstract     = {The magnetization of a ferro- or ferri-magnetic material has been<br/><br>
 modeled with the Landau-Lifshitz-Gilbert (LLG) equation. In this<br/><br>
 model demagnetization effects are included. By applying a linearized<br/><br>
 small signal model of the LLG equation, it was found that the<br/><br>
 material can be described by an effective permeability and with the<br/><br>
 aid of a static external biasing field, the material can be switched<br/><br>
 between a Lorentz-like material and a material that exhibits a<br/><br>
 magnetic conductivity. Furthermore, the reflection coefficient for<br/><br>
 normally impinging waves on a PEC covered with a<br/><br>
 ferro/ferri-magnetic material, biased in the normal direction, is<br/><br>
 calculated. When the material is switched into the resonance mode,<br/><br>
 we found that there will be two distinct resonance frequencies in<br/><br>
 the reflection coefficient, one associated with the precession<br/><br>
 frequency of the magnetization and one associated with the thickness<br/><br>
 of the layer. The former of these resonance frequencies can be<br/><br>
 controlled by the bias field and for a bias field strength close to<br/><br>
 the saturation magnetization, where the material starts to exhibit a<br/><br>
 magnetic conductivity, one can achieve low reflection (around -20<br/><br>
 dB) for a quite large bandwidth (more than two decades).},
  author       = {Ramprecht, Jörgen and Sjöberg, Daniel},
  institution  = {[Publisher information missing]},
  language     = {eng},
  pages        = {29},
  series       = {Technical Report LUTEDX/(TEAT-7155)/1-29/(2007)},
  title        = {Biased magnetic materials in RAM applications},
  volume       = {TEAT-7155},
  year         = {2007},
}