| Abstract: | The Néel thermal-activation theory of remanence in monodomain grains has been verified quantitatively in experiments on four ferrite micropowders and two natural rocks. Magnetization and demagnetization curves of thermal, isothermal, viscous, and anhysteretic remanences can all be predicted with reasonable accuracy when the Neél theory is generalized to include effects of grain interaction. Results with the natural materials indicate that interacting, single-domain grains or regions are the carriers of the magnetically hard natural remanence of some paleomagnetic rocks. |
