Enhancement of delay spectra in single-crystal yttrium-iron garnet by polycrystalline samples

S band experiments are reported on spin-acoustic delay modes in single-crystal yttrium-iron-garnet disc and rod specimens loaded with polycrystalline-hybrid garnet specimens in the form of discs and rings. Significant modifications of the d.c. internal-field distribution then take place, leading usually to a double-branch behaviour in the delay/field characteristics for a ring-loaded rod. Artificially increasing the thickness of axially magnetised discs leads to the induction of an axial delay mode.