Magnetoelectric excitations in multiferroic Ni3TeO6

The spin-order-induced ferroelectric antiferromagnet Ni3TeO6 transcends the magnetoelectric performance of all other single-phase multiferroics because it exhibits nonhysteretic colossal magnetoelectric coupling [Y. S. Oh, S. Artyukhin, J. J. Yang, V. Zapf, J. W. Kim, D. Vanderbilt, and S.-W. Cheong, Nat Commun. 5, 3201 (2014)]. We investigated spin and lattice excitations in Ni3TeO6 by a combination of infrared, Raman, and THz spectroscopies. Two spin excitations (near 13 and 35 cm(-1)) were observed simultaneously in Raman and time-domain THz spectra below the Neel temperature T-N = 53 K. We propose to assign them to electromagnons, which are activated by the dynamic magnetoelectric coupling. A third magnon is seen only in the Raman spectra near 206 cm(-1).