Spin-assisted ferroelectricity in ferrimagnetic CaBaCo4O7
Abstract
Dielectric and polarization measurements of the noncentrosymmetric “114” cobaltite CaBaCo4O7 were carried out on polycrystalline pellets. Our results show that this material exhibits a clear dielectric peak at TC and polarization in the ferrimagnetic state below TC = 70 K. The ferroelectric nature of this phase is supported by pyroelectric measurements. It is shown that this multiferroic material exhibits a magnetodielectric effect of 16% under 14 T just below TC. In the absence of any structural transition in the whole temperature range (300-4 K), the emergence of polarization at TC suggests that the ferrimagnetic ordering induces or assists the ferroelectricity. The symmetry analysis shows that in the magnetic phase the Heesch-Schubnikov point group is m'm2', which offers a unique potential for the possible coexistence of ferroelectricity, ferromagnetism, and ferrotoroidicity in this compound along three directions oriented at 90°.
- Publication:
-
Physical Review B
- Pub Date:
- July 2012
- DOI:
- 10.1103/PhysRevB.86.024410
- Bibcode:
- 2012PhRvB..86b4410S
- Keywords:
-
- 75.85.+t;
- 75.25.-j;
- 77.80.-e;
- Ferroelectricity and antiferroelectricity