Mössbauer effect used to study rare-earth oxides synthesized by a high-pressure method.

In the present paper the double rare-earth oxide solid solutions (EuR)O/sub 3/ (R = Gd, Dy, Ho, Er, Yb, Lu) are synthesized for the first time with a combination of high pressure and high temperature (3.0 GPa and 1080--1250 /sup 0/C). The analysis of x-ray diffraction shows that all products are B type (monoclinic) structures of single phase. Considering etanot =0 the /sup 151/Eu Moessbauer spectra were fitted by twelve transition lines. It is shown that the isomer shift depends on the unit-cell volume V/sup 1/3/ in a linear fashion.