Short: Simple Sim. of magnetization. V1.0 Author: gp@ict.fhg.de (Georg Pfundt) Uploader: gp ict fhg de (Georg Pfundt) Type: misc/sci Version: 1.0 Architecture: m68k-amigaos Kurz: Einfache Sim. spont. Magnetisierung. V1.0 1 Some Physics -------------- This program is a simple simulation of the phenomena of spontaneous magnetization. The idea is taken from [1]. A field of magnetic dipoles is randomly setup. The dipoles initialy show up or down with a certain probability. When the simulation starts, a dipole is picked out and only if the sum over its four neighbour spins is zero, it is flipped. The used theorie tells, that there is no change in overall energy in this case, but the overall magnetiztion is changed. If you start with a spin-distribution of 50% showing up, you get the state at very high temperatures with nearly zero magnetization. If you change the distribution to about 8% showing up (=92% showing down), you are at the curie-point. Over 8%, magnetization will disapear slowly, below 8% it stays finit, this is the spontaneous magnetization. 2 The Program ------------- You can start the program from workbench with standart arguments or from CLI with your arguments. CLI-Usage is: Magnet [-w width] [-h height] [-l level] [-?] [?] Width and Height are the outer window sizes (use -1 for full size). Level is the inital spin distribution percentage in 1/1000 (range 0-1000). Set level to 500 for equal distribution or to 80 for curiepoint. There is also a binary version for 68040: Magnet040. 3 The Source ------------ The program is written in C++ with SAS-C 6.55. The source code is included and absolutely PUBLIC DOMAIN, as far as it is not used for military purposes! The source contains a simple C++ window-class, that might be usefull for programmers. 4 The Author ------------ Georg Pfundt, Physics student, Universität Karlsruhe, Germany E-Mail: gp@ict.fhg.de Homepage till Dec. 1996: http://fphvax.rz.uni-karlsruhe.de/~pfundt Homepage will move to: http://www.rz.uni-karlsruhe.de/~ut53 Literature ---------- [1] Dietrich Stauffer; "Theoretische Physik : ein Kurzlehrbuch und Repetitorium", Springer Verlag Berlin, Heidelberg, New York, 1989. ISBN 3-540-50697-7 (Berlin ...), ISBN 0-387-50697-7 (New York ...)