Supplementary materials – RiTM

OOMMF Utilities 1.0

Xelur — Wed, 23 Apr 2014 14:52:28 +0000

Object Oriented Micromagnetic Framework (OOMMF) is free, portable, extensible public domain micromagnetic program and associated tools, which was developed at the National Institute of Standards and Technology (NIST). OOMMF is very powerful and useful tool which can be thinly configured for different micromagnetic studies, but at the same time, it has one drawback — the multiformat output. This situation arose from a huge history of the project and different problems that have appeared before it, but it required a global solution.

For this goal our group created an additional package to the Wolfram Mathematica framework which was called “oommfUtilities” and can get micromagnetic data from each OOMMF-snapshot (.ovf or .omf-files) and it does not matter what the format of this file was: text or binary. Also our package can read the tabular text data which is hold on in .odr-files.

oommfUtilities.zip

In this archive one can find the main package, documentation, several OOMMF-snapshots and example-file for fun. Enjoy!

If you have any questions or suggestions, write to me: [encode_email email=”alexey@volkov.ca” display=”alexey@volkov.ca”]

The results of scientific workshop: Spin-polarized current and spin-transfer torque

Xelur — Mon, 04 Feb 2013 17:21:49 +0000

According to the results of the scientific workshop I want to publish final presentation and put it to the free access, you can find it by the link: Download

Bloch Point Structure in a Magnetic Nanosphere

engraver — Fri, 16 Dec 2011 12:11:09 +0000

Authors:

Oleksandr V. Pylypovskyi, Denis D. Sheka, Yuri Gaididei

Publication:

Phys. Rev. B 85, 224401 (2012), 10.1103/PhysRevB.85.224401

Comments:

8 pages, 7 figures

arXiv:

http://arxiv.org/abs/1112.2413

The micromagnetic singularity, the so–called Bloch point, can form a metastable state in the nanosphere. We classify possible types of Bloch points and derive analytically the shape of magnetization distribution inside diﬀerent Bloch point. We show that external gradient ﬁeld can stabilize the Bloch point: the shape of the Bloch point becomes radial–dependent one and compute the magnetization structure of the nanosphere, which is in a good agrement with performed spin–lattice simulations.

Supplementary materials

Bloch point relaxation in a nanosphere

Sphere diamter
Exchange length
External magnetic field
Damping parameter
Time is measured in

Here is lattice constant.

(English) Controlled vortex core switching in a magnetic nanodisk by a rotating field

vkravchuk — Tue, 13 Nov 2007 18:24:42 +0000

Translation under construction.

Vortex polarity switching by a spin-polarized current

sheka — Tue, 13 Nov 2007 18:14:15 +0000

Authors:

Jean-Guy Caputo, Yuri Gaididei, Franz G. Mertens, Denis D. Sheka,

Publication:

Phys. Rev. Lett. 98, 056604 (2007), 10.1103/PhysRevLett.98.056604

Comments:

4 pages, 3 figures

arXiv:

http://arxiv.org/abs/cond-mat/0607362

The spin-transfer effect is investigated for the vortex state of a magnetic nanodot. A spin current is shown to act similarly to an effective magnetic field perpendicular to the nanodot. Then a vortex with magnetization (polarity) parallel to the current polarization is energetically favorable. Following a simple energy analysis and using direct spin-lattice simulations, we predict the polarity switching of a vortex. For magnetic storage devices, an electric current is more effective to switch the polarity of a vortex in a nanodot than the magnetic field.

Supplementary materials

Switching picture from numerical simulations on a square lattice with circular boundary.

Disk diamter	200a
Anisotropy coefficient	0.03 a
Damping coefficient	0.01
Degree of spin polarization	0.25
Spin current	-0.003