- Styliani Skiadopoulou: Magnetoelectric excitations in Ni-based multiferroic Tellurides
- 21. 10. 2015, 14:50
- lecture room F2, first floor Ke Karlovu 5
- more information
Abstract:
The multiferroic Ni3TeO6 exhibits non-hysteretic colossal magnetoelectric effect.1 A collinear antiferromagnetic order appears below 52 K, giving rise to spin-induced-ferroelectric order. A spin-flop transition takes place above approximately 6 T. The lack of hysteretic behavior in the magnetic field dependence of magnetization and dielectric constant precludes losses, highly promising for a series of magnetoelectric applications. Based on this concept, new Ni-based multiferroic telluride systems, Ni3-xCoxTeO6 and Ni3-xMnxTeO6, were studied. Both systems exhibit spin-order-induced ferroelectric order, with strong magnetoelectric coupling.
Magnetization, capacitance and pyrocurrent measurements at external magnetic field were conducted. Infrared, time-domain THz and Raman spectroscopy experiments were carried out for a temperature range of 5 to 300 K. Time-domain THz spectroscopy at external magnetic field was used at selected temperatures, below and close to the antiferromagnetic phase transition. The static ferroelectric polarization is influenced by the external magnetic field, indicating the spin-flop transition. In addition, a dynamic magnetoelectric coupling is observed, by tuning of the THz spectra with magnetic field. Such tuning is primarily due to the presence of electromagnons, which are also Raman active.
1. Yoon Seok Oh, Sergey Artyukhin, Jun Jie Yang, Vivien Zapf, Jae Wook Kim, David Vanderbilt & Sang-Wook Cheong, Nature Communications, 5, 3201 (2014)