Magnetostriction of antiferromagnetic iron and chromium garnet single crystals

The static magnetostriction of antiferromagnetic garnet single crystals Ca3Fe2Ge3O12 and Ca3Cr2Ge3O12 is measured at 4.2°K. It is shown that the angular dependences of the magnetostriction are characterized by equilibrium spin configurations occurring in cubic antiferromagnets in spin-flop fields. The magnetostriction fields H1 and H2, whose magnitudes confirm the existence of a significant magnetoelastic gap in the AFMR spectrum of the iron and chromium garnets investigated, are computed on the basis of the values obtained for λ100 and λ111.