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Magnetization curves at 1 K with a magnetic field applied along the x direction are reported for two typical single crystals of TbFeO3. The different behaviors which have been observed, are ascribed to a partial quenching of domains in one of the samples. This quenching is at the origin of the important temperature dependent discrepancies between the two samples2.

The low temperature magnetic properties of TbFeO3 are well accounted for by ascribing a leading part to dipolar interactions. The issue of the competition between the two ordered magnetic phases observed experimentally depends then in a crucial way on the demagnetizing factor associated with the shape of the sample. A theoretical phase diagram is introduced, which defines, at zero applied field, the stability domains of the different possible structures as functions of temperature and demagnetizing factor, assuming purely dipolar rare-earth interactions. The introduction of exchange interactions leads to a modified phase diagram which allows interpretation of the somewhat contradictory results observed on different samples.

Absence of significant exchange coupling between Fe and Tb moments in TbFeO3 leaves dipolar interactions as preponderant in determining low temperature structures. Therefore, the nature of the stable structure at given temperature depends upon (and is approximately predicted as a “function” of) the shape of the sample.