1 / 5

magnetic moment vs. electric field @ H=0

magnetic moment vs. electric field @ H=0. magnetoelectric coefficient. -rhombohedral corundum type structure.  Cr 2 O 3 moments can order in two different 180° domains. -noncentrosymmetric magnetic point group. Cr moments have opposite direction with respect to the arrangement

craig
Télécharger la présentation

magnetic moment vs. electric field @ H=0

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. magnetic moment vs. electric field @ H=0 magnetoelectric coefficient -rhombohedral corundum type structure Cr2O3 moments can order in two different 180° domains -noncentrosymmetric magnetic point group Cr moments have opposite direction with respect to the arrangement of oxygen ligands @T<TN=308K Magnetoelectric effect of Cr2O3 measured by SQUID-magnetometry

  2. @T>0 magn. field creates magnetization Ansatz Origin of the magneto-electric effect  Phenomenological theory, Rado (1961) fictitious field, h, such that ~sublattice magnetization

  3. single ion terms no interaction with neighbors A Cr3+- coordination B  why becomes α negative for T0 ?  what is the microscopic origin of h ? Microscopic view  Hamiltonian of a single Cr3+-Ion in the crystal field E = 0 E = 0 where

  4. A Cr3+,S=3/2 u u B Cr3+ shifted towards A A B shifted towards B O2-  E shifts Cr3+-ions in field direction

  5.  Interaction term exchange interaction where mean field approximation  Interaction term for one ion on place A/B where  electric induced exchange and g-shift seem to dominate in Cr2O3

More Related