Magneto-orbital helices and multiferroicity

Autor: Perks, N. J., Johnson, R. D., Martin, C., Chapon, L. C., Radaelli, P. G.
Rok vydání: 2012
Předmět:
Druh dokumentu: Working Paper
Popis: Orbitally ordered states evolving coincidentally with structural distortions and magnetic ordering provide a novel route to controlling electronic and magnetic properties of materials through external fields. We report an unprecedented magneto-orbital helix in CaMn7O12, found to give rise to the largest magnetically induced ferroelectric polarisation measured to date. Characterisation of the structural modulation using x-ray diffraction, and analysis of magnetic exchange shows that orbital order is crucial in stabilising a chiral magnetic structure, thus allowing for electric polarisation. Additionally, the presence of a global structural rotation enables the coupling between this polarisation and magnetic helicity required for multiferrocitiy. These novel principles open up the possibility of discovering new high-temperature multiferroics.
Comment: Submitted to Nature Communications
Databáze: arXiv