PC Micromagnetics Simulator Release
The PC Micromagnetic Simulator (SimulMag) is a personal computer
based magnetic design tool developed by John Oti while he was in the
Electromagnetic Technology Division of EEEL/NIST. This software is no
longer being developed or supported at NIST, and is provided "as is."
These pages are based on earlier pages written by John Oti.
Brief introduction to the
The simulator allows one to construct a magnetic device or circuit and
simulate the system response under the influence of external magnetic fields,
currents, or local field sources. The program is expected to be most useful
as an effective tool in the development of initial device design concepts
and their rapid iterative analyses before rigorous modeling is attempted.
The software may also have potential pedagogical uses for classroom instruction
The software requires Windows 95 or Windows NT 3.51 or higher to run.
Available on this web site are beta versions of the micromagnetics
simulator (Simulmag v2.0j) and the design viewer program (MMS Viewer
v2.0i), design file examples illustrating software features and the
user's manual with addendum. Features include:
- Parametric simulation capability in which geometric and magnetic
properties of elements making up a design as well as the applied
external field properties, can be systematically varied in a
sequence of simulation runs. Output is in the form of surface plots
formed from the curve characteristics obtained for individual
parameter values. Additional output such as planar slices of the
surface plots are generated using analysis tools available in the
- Simulation of soft-magnetic elements using a
demagnetization-modified permeability model.
- External field pulse application capability.
- More robust and accurate computational engine.
- Backward compatibility to previous version design files.
- Unprecedented visualization of interacting magnetic objects is
- The geometry and the magnetic states of a completed design are
displayed in three dimensions. The analysis is based on a collection
of single-domain elements whose size and position can be specified
by the designer.
- The elements may be magnetic or nonmagnetic, a conductor or an
insulator. The elements' magnetic properties, such as
magnetization, anisotropy, pinning fields, resistivity must be
specified or selected from a library of materials.
- Electrical circuits can be specified and currents applied.
- The elements interact via magnetostatic interactions and user
specified exchange interactions.
- The magnetization processes in a design are simulated using
static and dynamic (Landau-Lifshitz) calculation methods.
- The elements are arranged in groups to allow different
structures to be built up and manipulated independently. Relative
motion between the groups can be specified. For example one can
design a group that describes an advanced recording head and a group
describing the magnetic structure in media. These two groups can
then be moved relative to each other in a way to simulate the
- The program output consists of a movie of the evolution of
magnetic moments of all of the elements, plots of the magnetization
of either the whole system or user-defined groups, and plots of the
magnetoresistance of the system or user-defined groups.
- A simulation can be recorded for later playback.
- The configuration of a design, a recorded simulation and the
output data can be conveniently saved to disk files for further
Navigating this site
Using the following links you will be able to obtain copies of the
simulator program, a simulation viewer program (MMS Viewer), the
user's manual, design examples and answers to commonly asked questions
concerning the software. The viewer program automatically plays back
recorded simulations and permits viewing and saving to file of all
simulation data. When installed the viewer is much smaller than the
simulator program and can be used as a plug-in in your web browser for
convenient online viewing of design examples. This will enable you to
readily evaluate the capabilities of the software before embarking on
your own designs with the simulator. The system requirements for the
viewer program are the same as for the simulator.
The calculated results do not necessarily describe what would be
realized from an actual experimental measurement. All magnetic
simulators perform idealized calculations and cannot necessarily
describe effects resulting from fine details inherently present in
real magnetic samples. This program is based on a relatively simple
single-domain model for speed of calculation. Other techniques may
produce different results. Interested users are invited to review the
information of the NIST muMAG
Commercial equipment and software referred to on these pages are
identified for informational purposes only, and does not imply
recommendation of or endorsement by the National Institute of Standards
and Technology, nor does it imply that the products so identified are
necessarily the best available for the purpose.
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Date created: February 10, 1999 | Last updated: April 27, 2011