Related papers: Coupling of phonons and electromagnons in GdMnO_3
We study the existence of incommensurate phases in the phase diagram of the two orbital double exchange model coupled with Jahn-Teller phonons and with superexchange interactions. In agreement with experimental results, we find that undoped…
We have investigated temperature and magnetic-field dependence of dielectric properties in the orthorhombic GdMnO$_3$ single crystal which is located near the phase boundary between the ferroelectric/spiral-antiferromagnetic phase and the…
Terahertz and far-infrared electric and magnetic responses of hexagonal piezomagnetic YMnO3 single crystals are investigated. Antiferromagnetic resonance is observed in the spectra of magnetic permeability mu_a [H(omega) oriented within the…
At room temperature, GdMnO3 is a paraelectric and paramagnetic with a distorted perovskite structure of orthorhombic symmetry (space group Pnma). On cooling, it undergoes a phase transition sequence to a magnetic incommensurate phase…
Spin and lattice dynamics of CaMn7O12 ceramics were investigated using infrared, THz and inelastic neutron scattering (INS) spectroscopies in the temperature range 2 to 590 K, and, at low temperatures, in applied magnetic fields of up to 12…
The lattice dynamics of the $\rm YMnO_3$ magneto-electric compound has been investigated using density functional calculations, both in the ferroelectric and the paraelectric phases. The coherence between the computed and experimental data…
Magnetic and magnetoelectric excitations in the multiferroic TbMnO_3 have been investigated at terahertz frequencies. Using different experimental geometries we can clearly separate the electro-active excitations (electromagnons) from the…
Magnetodielectric materials are characterized by a strong coupling of magnetic and dielectric properties and in rare cases simultaneously exhibit both, magnetic and polar order. Among other multiferroics, TbMnO3 and GdMnO3 reveal a strong…
We report the low-temperature coexistence in NdFe3(BO3)4 of an incommensurate magnetic phase with a strained commensurate magnetic phase that is primarily at the surface of the crystal. Increasing the temperature or magnetic field decreases…
We have studied the impact of the magnetic field on the electromagnon excitations in TbMnO3 crystal. Applying magnetic field along the c axis, we show that the electromagnons transform into pure antiferromagnetic modes, losing their polar…
We determine the nature of coupled phonons and magnetic excitations in AlFeO3 using inelastic light scattering from 5 K to 315 K covering a spectral range from 100-2200 cm-1 and complementary first-principles density functional theory-based…
We measured the temperature dependent infrared reflectivity spectra of TbMnO3 with the electric field of light polarized along each of the three crystallographic axes. We analyzed the effect, on the phonon spectra, of the different phase…
Reflection and transmission as a function of temperature have been measured on a single crystal of the magnetoelectric ferrimagnetic compound Cu$_{2}$OSeO$_{3}$ utilizing light spanning the far infrared to the visible portions of the…
The interaction of light in terahertz frequency region with electromagnons in a sinusoidal incommensurate magnetic state in TbMnO3 is studied. A significant change in the frequency dependence of the dielectric constant e_zz near the…
The interplay of the electron-phonon interaction and of the double and super exchange magnetic effects is analyzed in the $La_{1-x}Ca_xMnO_3$ perovskites with $0<x<0.5$. By using an analytical variational scheme that allows to treat the…
We report on far- and mid-infrared reflectivity of NdMnO3 from 4 K to 300K. Two main features are distinguished in the infrared spectra: active phonons in agreement with the expected for orthorhombic D2h 16-Pbnm (Z=4) space group remaining…
We present the results of transmittance experiments on GdMnO3 multiferroic manganite in the far infrared frequency range. The spectra allow to obtain the positions and the intensity of the high frequency electromagnon (~ 75 cm-1) in this…
EuTiO3 (ETO) has recently experienced an enormous revival of interest because of its possible multiferroic properties which are currently in the focus of research. Unfortunately ETO is an unlikely candidate for enlarged multifunctionality…
GdMnO$_3$ shows an incommensurate antiferromagnetic order below $\simeq 42$ K, transforms into a canted A-type antiferromagnet below $\simeq 20$ K, and for finite magnetic fields along the b axis ferroelectric order occurs below $\simeq 12$…
The thermal conductivity \kappa of Cu_1-xMg_xGeO_3 is measured in magnetic fields up to 16 T. At the transition field H_c to the high-field incommensurate (I) phase, \kappa abruptly decreases. While \kappa of the pure CuGeO_3 is enhanced…