TY - JOUR
T1 - Far-IR magnetospectroscopy of magnons and electromagnons in TbFe O3 single crystals at low temperatures
AU - Stanislavchuk, T. N.
AU - Wang, Yazhong
AU - Cheong, S. W.
AU - Sirenko, A. A.
N1 - Publisher Copyright:
© 2017 American Physical Society.
PY - 2017/2/21
Y1 - 2017/2/21
N2 - Transmittance spectra of TbFeO3 single crystals have been studied in the far-infrared spectral range 15-120cm-1 in the external magnetic fields up to 9 T and at low temperatures down to 1.5 K. The temperature and magnetic-field dependencies of the antiferromagnetic resonance (AFMR) modes have been measured below and above the magnetic ordering temperature of Tb moments TNTb=3.3K. Both the quasiferromagnetic and quasiantiferromagnetic modes of AFMR demonstrate hardening at T<TNTb. The quasiantiferromagnetic mode gains electric-dipole activity along the c axis below TNTb and thus behaves as a hybrid, i.e., both electric- and magnetic-dipole active, mode. In addition to AFMR modes, below TNTb we observed the appearance of electromagnon excitation at about 27cm-1, which is electric-dipole active along the c axis. The electromagnon is optically active only in a narrow temperature range, 2.7K<T<TNTb at H=0, and in a narrow range of magnetic fields 2.4-2.7 T applied along the b axis at T=1.5K. We argue that this electromagnon appears in magnetic phases, which are compatible with a spontaneous electric polarization along the b axis.
AB - Transmittance spectra of TbFeO3 single crystals have been studied in the far-infrared spectral range 15-120cm-1 in the external magnetic fields up to 9 T and at low temperatures down to 1.5 K. The temperature and magnetic-field dependencies of the antiferromagnetic resonance (AFMR) modes have been measured below and above the magnetic ordering temperature of Tb moments TNTb=3.3K. Both the quasiferromagnetic and quasiantiferromagnetic modes of AFMR demonstrate hardening at T<TNTb. The quasiantiferromagnetic mode gains electric-dipole activity along the c axis below TNTb and thus behaves as a hybrid, i.e., both electric- and magnetic-dipole active, mode. In addition to AFMR modes, below TNTb we observed the appearance of electromagnon excitation at about 27cm-1, which is electric-dipole active along the c axis. The electromagnon is optically active only in a narrow temperature range, 2.7K<T<TNTb at H=0, and in a narrow range of magnetic fields 2.4-2.7 T applied along the b axis at T=1.5K. We argue that this electromagnon appears in magnetic phases, which are compatible with a spontaneous electric polarization along the b axis.
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U2 - 10.1103/PhysRevB.95.054427
DO - 10.1103/PhysRevB.95.054427
M3 - Article
AN - SCOPUS:85014576850
VL - 95
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 0163-1829
IS - 5
M1 - 054427
ER -