This work deals with the behavior of the macroscopic magnetic properties of ringhyphen;shaped polycrystalline yttriumhyphen;iron garnets (YIG) under the action of compressive stresses applied parallel to the measurement direction along the director circles. For this purpose, a highhyphen;pressure cell has been designed consisting of a hydrostatic pressure application on the outer side of the ring. The results are separated in two parts according to the sample used: The first one is concerned with YIG samples called lsquo;lsquo;type Drsquo;rsquo; and so defined because of the dispersed nature of their natural domainhyphen;wall configuration. The second one is concerned with YIG samples called lsquo;lsquo;type Trsquo;rsquo; and so defined because of the toroidal character of their natural domainhyphen;wall configuration. It is shown that the first category (typehyphen;D samples) gives results in good agreement with the classical theory of the magnetoelasticity, while the second (typehyphen;T samples) gives results altogether inconsistent. The difference of behavior between the two types of samples is explained by the difference between their domainhyphen;wall configuration in the spontaneous state. A wellhyphen;tried theoretical model is used for the general interpretation.
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