Abstract
Detailed evidence is presented linking the Raman spectra in the magnetic semiconductors EuSe and EuS to their respective magnetic phase diagrams. In particular, spectra for EuSe are presented for the paramagnetic, ferromagnetic, antiferromagnetic (up-arrowup-arrowarrow-downarrow-down), and ferrimagnetic (up-arrowup-arrowarrow-down) spin arrangements and are related to a Brillouin-zone-folding scheme for each magnetic sublattice structure. Based on our spectra a set of phonon dispersion relations for EuSe in the GAMMA-L direction is constructed. We have also obtained for the first time right-angle Raman scattering spectra in EuSe. These results are compared with those obtained in the back-scattering geometry. Of significance is our observation that the broad spectral line extending from ..omega../sub TO/ to ..omega../sub LO/ in the paramagnetic phase persists for laser excitation energies below the fundamental absorption edge, thereby ruling out a hot luminescence mechanism for this feature. Instead, our results are consistent with a spin-disorder model. Resonant Raman enhancement results are given for scattering in ferromagnetically ordered EuS and EuSe, and are related to magnetic-field-modulated magnetoreflectivity spectra. Particular attention has been given to the magnetic-phase dependence of the EuSe modulated spectra in going from the ferrimagnetic to the ferromagnetic spin arrangements.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
