Submission Guidelines muMag Standard Problem #1

1. The problem is to calculate complete hysteresis loops for a 1x2 micron permalloy rectangle (20 nm thick), where the applied field is stepped from +50 mT (+500 Oe) to -50 mT (-500 Oe), and back to +50 mT (+500 Oe). You may choose any cell size and geometry, and may step the field as desired, although a remanent (0 field) state is required. This is to be done twice, once with the applied field parallel to the long (y-) axis of the rectangle, and once with the applied field parallel to the short (x-) axis. Due to the presence of meta-stable symmetric states, the applied fields should be rotated 1 degree counterclockwise off the nominal axis, if possible. The initial state at +50 mT is not specified, but should resemble a saturated state. If you want, you may begin at a higher field and step down to +50 mT. Our reports will be restricted to the data between +50 mT and -50 mT, however.
2. The material and geometry parameters can be found at http://www.ctcms.nist.gov/~rdm/stdprob_1.html
3. The coordinate system to be used is:

                    y-axis
                   ^
                   |
                   |
                   --------  -
                   |      |  ^
                   |<-1-->|  |
                   |micron|  |
                   |      |  |
                   |      |  |
                   |      |  2 microns
                   |      |  |
                   |      |  |
                   |      |  |
                   |      |  |
                   ----------------> x-axis
   

   and z-axis pointing out of the plane (right hand system). The entire sample lies in the first octant, i.e., 0<=x<=1, 0<=y<=2, and 0<=z<=0.020 (units are microns).
4. You agree to allow us to report/publish your submission in conjunction with other submissions as we deem fit. We will take reasonable steps to keep submissions anonymous. You will be assigned a submission code that will be used to tag your results in all reports. This will make it easy for you to see how your results compare with others, and will be a bookkeeping aid for us. To request a submission code send email to

   mumag-prob1@cobalt.nist.gov

   with

   Subject: Submission code request

5. Updates, corrections and additions to submissions will be accepted. Email to mumag-prob1@cobalt.nist.gov for more information.

1. XXXXXdsc.txt
   Description of your solution technique, details below in Appendix A.
2. XXXXXhyx.dat, XXXXXhyy.dat
   m vs. H data for field applied approx. along the x (short), resp. y (long) axis, format defined in Appendix B, below.
3. XXXXXrx1.dat, XXXXXrx2.dat, XXXXXry1.dat, XXXXXry2.dat
   Raw ASCII data; Magnetization m as a function of position at remanence. See Appendix C. For 3D grids, this should be a slice through the center of the rectangle, parallel to the x-y plane. The rx files are for remanent states resulting from application of the field parallel to the short (x) axis, with rx1 coming down from +50 mT, and rx2 coming up from -50 mT. The second file, rx2, is optional, and should only be included if you feel it shows significant difference from rx1. The ry files are for the corresponding remanent states resulting from field application along the long (y) axis.
4. XXXXXvx1.ps, XXXXXvx2.ps, XXXXXvy1.ps, XXXXXvy2.ps
   Vector (arrow or cone) plots of magnetization at remanent (0 field) state, as a PostScript file, corresponding to the states depicted by the raw data files rx1, rx2, ry1 and ry2, respectively. The submission of these vector plots is encouraged but optional, because some have expressed concern that idiosyncrasies of arrow style may reveal the identity of the submitter. If you prefer, you may submit raw ASCII data in the same format as for the XXXXXrx1.dat file, and we will produce a standardized PostScript vector plot using all the data in this file. File names in this case should be XXXXXvx1.dat, etc. Alternately we will use the information from (for example) the XXXXXrx1.dat file directly, but for dense meshes the arrows might not be very distinguishable.

The above files should be collected into either a gzipped-tar or a zip archive, with your submission code as the base name (e.g., aa96a.zip). Transmit your results either by email (after uuencode'ing, mpack'ing or adding as an attachment - please, no binhex) to

mumag-prob1@cobalt.nist.gov

with

Subject: XXXXX results-email

where XXXXX is your submission code. To protect anonymity, be sure the only identifying notation in these files is your submission code.

Submission code:
Units (SI or Gaussian):
Dimensionality of magnetizations (2D or 3D):
Dimensionality of grid (2D or 3D):
Average cell dimensions (length x width x height, in nm):
Total number of cells:
Initial state (uniform/random/other):
Number of field states calculated (inc. +/-50 mT) for x-loop/y-loop:
Canting angle of applied field from nominal axis (degrees):
Demag calculation technique:
Solver method (e.g., LLG/Runge-Kutta, Energy min./Conj. grad.):
Solver stopping criteria:
Hardware: processor type/speed (MHz):
          main memory size (MB):
          L1/L2 cache size (KB/KB):
Execution time (minutes) x-loop/y-loop:
Remanent magnetization (m_x,m_y,m_z) (reduced units), x-loop:
                                                      y-loop:
Coercive field H_c (mT or Oe), x-loop/y-loop:
Special conditions:
Other comments:

     Step_no   H_x   H_y   H_z   m_x   m_y   m_z

In addition, comment lines are allowed. These are denoted by a # in the first column. The first line should be a comment line containing the file name (with your embedded submission code), and the second should be a comment line indicating your choice of units for the applied field. Valid units include: kA/m, A/m, T, mT, kOe, Oe, G, kG.

A (short) sample hyy.dat file follows:

# File: aa96ahyy
# Units: T
# Sample hyy.dat file, 2-Feb-96.  The first 8 lines illustrate the
# use of comments.  The first two comment lines are required.  The
# Unit field should be one of kA/m, A/m, T, mT, kOe, Oe, G, or kG.
# Note: This is an entirely *fictional* example.
#
# Step  B_x(T)     B_y(T)   B_z(T)  m_x       m_y       m_z
   1     0          .0500    0.0    0.000     0.986     0.000
   2     0          .0100    0.0    0.000     0.953     0.000
   3     0          .0050    0.0    0.100     0.905     0.000
# Notice that the field steps don't have to be regular
   4     0            0      0.0  0.000     0.623     0.000
   5     0         -.0500      0.0  0.000    -0.972     0.000
   6     0          0     0.0    0.003    -0.605      0.000
   7     0          .0500    0.0    0.0         0.975  0
# It is not required for the columns to line up, as long as
# there is at least 1 space character between successive columns.

At some time in the future, submissions will be accepted in HDF (Hierarchical Data Format), but at the present time we are requesting ascii files, with one 6-tuple per line, entries separated by space characters, like this:

# File: aa96arx1
# x(microns)  y(microns)  z(microns)   m_x    m_y    m_z
  0.005       0.005       0.010       -0.3    0.95    0
  0.015       0.005       0.010       -0.27   0.96    0
  0.025       0.005       0.010       -0.27   0.96    0
   :           :          :              :     :      :
   :           :          :              :     :      :
  0.995       0.005       0.010          0    1.0     0
  0.005       0.015       0.010          0    1.0     0
  0.015       0.015       0.010          0    1.0     0
  0.025       0.015       0.010          0    1.0     0
   :           :          :              :     :      :
   :           :          :              :     :      :
  0.995       1.995       0.010        0.3    0.91    0

Your data 6-tuples may be in any order and do *not* have to lie on a regular grid. We will sample your data onto a 100x200 grid (the actual sample point coordinates are those used in the preceding data file example) by using the magnetization at the closest point (i.e., a 1-point fit). For example, to fill in a value for location (x,y)=(0.025,0.015), we will scan through your data and find the (x,y) coordinate closest to (0.025,0.015), and just use the associated (m_x,m_y,m_z). If you want a more sophisticated interpolation scheme, you are free to interpolate the data yourself and submit XXXXXr??.dat files with exactly the sample points in the above example.

You may peruse the first standard problem submission reports, or return to the
muMag Site Directory.