High frequency susceptibility of a weak ferromagnet with magnetostrictive magnetoelectric coupling: using heterostructures to tailor electromagnon frequencies

摘要

In the first part of this work we calculate the high frequencymagnetoelectric susceptibility of a simultaneously ferroelectric and cantedantiferromagnetic (also know as weak ferromagnetic) thin film withmagnetostrictive magnetoelectric coupling. We show that a dynamic couplingexists between the ferroelectric and optic antiferromagnetic excitations. Inthe second part of the paper, we calculate using an effective medium method thesusceptibility of a heterostructure comprising alternating thin films of such amaterial together with a ferromagnet. Dipolar magnetic fields serve to couplethe ferromagnetic and optic antiferromagnetic modes, which in turn couples theferromagnetic and ferroelectric excitations. This provides a mechanism forcreating "electromagnon" modes in the microwave regime which may be useful forapplications.