Magnetic Studies at high pressures

Abstract

Of all the models mentioned, the one that comes closest to explaining the high pressure data on I and II is that due to Zimmermann and König (6). The model now proposed is an extension of a model that has become possible due to the additional results available at high pressures and on two different compounds. The model outlined here is thus essentially based on the above-mentioned one, but includes the pressure dependence of the strength of the strain interaction r'. Pressures are not reduced so drastically as in the case of compound I. The above simple model seems to explain the high pressure results. It would be interesting to know the experimentally determined compressibilities of the two spin states of compounds I and II, and it will also be a test of the above model. The other aspect of the spin state transitions revealed by the present studies is that the 'residual paramagnetism' in the low temperature phase increases with pressure. This has led to the conclusion that a potential barrier separating the high and low spin states exists and this increases with pressure.