Single crystals of multiferroic cobalt chromite Co (Cr2-x Cox) O4 have been grown via several methods to have different Co3+ doping levels (x=0.0, 0.14, and 0.18). Under magnetic fields, all the crystals display electric polarization reversal below their spiral spin ordering temperatures. We find that both saturated electric polarization and magnetization under magnetic fields increase significantly with the increase in x. This result can be qualitatively explained by a broken balance between at least two electric polarization contributions existing in CoCr2 O4 and is expected to be useful in tailoring electric polarization in similar kinds of multiferroics.
Bibliographical noteFunding Information:
We thank Greg Stewart for critical reading of our manuscript. This study was supported by the NRL program (Program No. M10600000238) and the KRF Grant (Grant No. KRF-2008-314-C00101) by MEST and the Fundamental R&D Program for Core Technology of Materials by MOKE. Ingyu Kim was supported by Seoul R&BD. The research carried out at POSTECH was supported by KOSEF (Grant No. R01-2007-000-11188-0) and POSTECH research fund. PLS was supported by MEST and POSTECH. JHC was supported by KOSEF (Grant No. R01-2008-000-10787-0).
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)