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Manuscript Title: A Fortran program for routine analysis of magnetic susceptibility data.
Authors: E.D. von Meerwall
Program title: SUSCEPT2
Catalogue identifier: ABNA_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 15(1978)237
Programming language: Fortran.
Computer: IBM 370/158.
Operating system: OS/VS2, OS/MVS.
RAM: 40K words
Word size: 8
Keywords: Solid state physics, Susceptibility magnetic, Faraday method, Curie-weiss law, Ferromagnetic correction, Temperature-independent, Susceptibility, Chi-square, Fit, Experiment.
Classification: 7.4.

Nature of problem:
Faraday susceptibility data in the form of balance readings are converted to susceptibilities, and optionally interpreted in terms of a Curie-Weiss temperature dependence.

Solution method:
Susceptibilities chi are calculated from the data via their definition: ferromagnetic corrections are made using a two-point extrapolation of chi(H) vs. 1/H to infinte field; Curie-Weiss interpretation is done on the results of a least-squares fit of chi**-1vs. T, where a temperature- independent chiO can also be fitted.

The present limit of 100 data points is easily extended.

Unusual features:
(1) For each temperature, chi values at one or two magnetic fields are found, with uncertainties, corrected for the weight and magnetism of sample supports. If chi is given at two fields, values are averaged or a ferromagnetic correction applied as appropriate. A constant ChiO value if supplied, is subtracted from all points.
(2) A calibration mode calculates apparatus constants given a sample of known susceptibility. Constants stay in effect until the next calibration; defaults may be provided.
(3) A fit of the data to the equation chi - chiO = C/(T - Tc) is optional, yielding C, Tc, and optionally chiO, above a cut-off temperature Tcut which may be zero, specified, or derived from the fit.
(4) Line printer plots of chi vs. T(and chi**-1 vs. T with the Curie- Weiss fit) are provided.

Running time:
On the IBM 370/158, the program compiles (G1 compiler) in about 8 CPU s. A typical case with full interpertation takes less than 3 CPU s.