Multiferroicity in the square-lattice antiferromagnet of Ba 2CoGe2O7

H. T. Yi, Y. J. Choi, S. Lee, S. W. Cheong

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64 Citations (Scopus)


We have discovered the appearance of ferroelectricity below the Neel temperature of 6.7 K in the antiferromagnetic Ba2CoGe 2O7 with square magnetic lattice. The ferroelectric polarization is rather small in magnitude and aligned along the c axis, but its magnitude increases remarkably and its direction rotates away smoothly from the c axis when magnetic fields are applied along the c axis. The electric polarization's behavior of smooth rotation, rather than a sudden flip, is unique. It also accompanies a linear increase in magnetization and a smooth change of dielectric constant with little hysteresis, which may be important for certain technological applications.

Original languageEnglish
Article number212904
JournalApplied Physics Letters
Issue number21
Publication statusPublished - 2008

Bibliographical note

Funding Information:
This work was supported by the MRSEC NSF-DMR-0520471.

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)


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