An "easy axis monitor" for the detailed study of spin transitions.application to ErFeO3and Er3Fe5O12

We describe a simple instrument to monitor the easy magnetic axis of a sample, particularly useful to study the mechanism of spin transitions. In this instrument, the sample is free to rotate in an external magnetic field, and to reach its lowest free energy state. The operating range is 1-300 K, extension to higher temperature being straightforward. Measurements of the spin transitions of ErFeO
3
and Er
3
Fe
5
O
12
are reported and discussed.