Static and Dynamic Magnetoelectric Coupling in Room-Temperature Multiferroic (Ba0.2Sr0.8)3Co2Fe24O41 with Z-type Hexaferrite Structure
Z-hexaferrite (Ba0.2Sr0.8)3Co2Fe24O41 is a spin-induced ferroelectric via inverse Dzyaloshinskii-Moriya mechanism. Static magnetic and magnetoelectric properties of ceramic sample were measured to compare the results with those of single crystal. THz, infrared and inelastic neutron scattering spectra were investigated in a broad range of temperatures. A sharp electromagnon is observed near 1 THz, vanishing with increasing magnetic field until a phase transition occurs at H~2T. Then, another strong peak whose resonance frequency is linearly proportional to the magnetic field turns up from the sub-THz range. We assign this peak to a ferrimagnetic resonance.