Misfit Strain in LPE

Misfit strain in epitaxial magnetic garnet films has been quantitatively investigated for ${\mathrm{Y}}_{\text{3−}\mathrm{x}}{\mathrm{Eu}}_{\mathrm{x}}{\mathrm{Fe}}_{\text{3.9}}{\mathrm{Ga}}_{\text{1.1}}{\mathrm{O}}_{12}$ deposited on (111) ${\mathrm{Gd}}_3{\mathrm{Ga}}_5{\mathrm{O}}_{12}$ substrate by LPE techniques. By the X‐ray double crystal method, measurements were carried out on the bending curvature, from which strain parallel to the surface, ^ε x, was directly derived. For small misfits, ^ε x is proportional to $\Delta \mathrm{a}$ , as expected from Besser's Region I model. However, in the region of $\Delta \mathrm{a}\text{≤−0.02Å}$ , it was confirmed that a distinct transient region exists between Region I and II, and some part of the elastic stress is relieved during the film growth. Degree of the elastic stress relief increases gradually with further increasing $\mathrm{|\Delta }\mathrm{a}|$ . Similar conclusions were derived from rocking curve measurements using symmetric and asymmetric reflections.