Related papers: Far-infrared optical excitations in multiferroic T…
We report electrical, magnetic, magnetodielectric and magnetoabsorption properties of a polycrystalline GaFeO3. The resistivity measurement shows that the sample is highly insulating below 200 K and the resistivity above 200 K obey the…
The (H,T)-phase diagram of the multiferroic perovskite TbMnO$_3$ was studied by high-resolution thermal expansion $\alpha(T)$ and magnetostriction $\Delta L(H)/L$ measurements. Below $T_{N}\simeq 42$ K, TbMnO$_3$ shows antiferromagnetic…
Neutron scattering measurements of the lowest-energy TO phonons in the relaxor Pb(Mg1/3Nb2/3)O3 (PMN) are reported for 10<=T<=750 K. The soft mode, which is overdamped by the polar nanoregions below the Burns temperature T_d = 620 K,…
The reflectivity of a large LuFe(2)O(4) single crystal has been measured with the radiation field either perpendicular or parallel to the c axis of its rhombohedral structure, from 10 to 500K, and from 7 to 16000 cm-1. The transition…
Hexagonal YMnO$_3$ is well known for the co-occurrence of ferroelectricity and antiferromagnetism at low temperatures. Using temperature-dependent spectroscopic ellipsometry at an $a$-plane oriented single crystal, we show how the…
Reflection and transmission as a function of temperature (5--300 K) have been measured on single crystals of the multiferroic compound FeTe$_{2}$O$_{5}$Br utilizing light spanning the far infrared to the visible portions of the…
We have investigated dielectric properties in Mott insulators GdMnO$_{3}$ and TbMnO$_{3}$ under magnetic fields and external quasihydrostatic pressures. In the case of GdMnO$_{3}$, thermal hysteresis for dielectric constant $\epsilon$ and…
The dielectric constant of multiferroic hexagonal HoMnO_3 exhibits an unprecedented diversity of anomalies at low temperatures (1.8 K< T <10 K) and under external magnetic fields related to magnetic phase transitions in the coupled system…
To clarify the controversy concerning the ferroelectricity of the lower temperature magnetic phases of Eu0.8Y0.2MnO3, hence its multiferroic character, we have studied in detail the temperature dependence of the electric polarization. The…
High-frequency dielectric studies of Bi_0.85Nd_0.15FeO_3 ceramics performed betweeen 100 and 900 K reveal hardening of most polar phonons on cooling below antiferroelectric phase transition, which occurs near 600 K. Moreover, a strong THz…
Polarized Raman scattering and infrared reflection spectra of hexagonal HoMnO$_3$ single crystals in the temperature range 10-300 K are reported. Group-theoretical analysis is performed and scattering selection rules for the second order…
The optical properties of Nd$_{0.7}$Sr$_{0.3}$MnO$_3$ thin films have been studied from 5 meV to 25 meV and from 0.25 eV to 3 eV, at temperatures from 15 K to 300 K and magnetic fields up to 8.9 T. A large transfer of spectral weight from…
We report on the temperature dependent Raman spectroscopic studies of orthorombic distorted perovskite YCrO3 in the temperature range of 20-300K. Temperature dependence of DC-magnetization measurement under field cooled and zero field…
Knowledge of the electronic band structure of multiferroic oxides, crucial for the understanding and tuning of photo-induced effects, remains very limited even in the model and thoroughly studied BiFeO3. Here, we investigate the electronic…
The resistivity in the ferromagnetic state of flux-grown La_{2/3}(Pb,Ca)_{1/3}MnO_3 single crystals, measured in magnetic fields up to 7 T, reveals a strong quadratic temperature dependence at and above 50 K. At lower temperatures, this…
The structural phase transition in hexagonal BaMnO$_3$ occurring at $T_c$=130 K was studied in ceramic samples using electron and X-ray diffraction, second harmonic generation as well as by dielectric and lattice dynamic spectroscopies. The…
In the colossal magnetoresistance manganites polarons have been proposed as the charge carrier state which localizes across the metal-insulator transition. The character of the polarons is still under debate. We present an assessment of…
We report the observation of a magnetic polarization of the O\,$2p$-states in YMn$_2$O$_5$ through the use of soft X-ray resonant scattering at the oxygen $K$-edge. Remarkably, we find that the temperature dependence of the integrated…
A neutron scattering investigation of the magnetoelectric coupling in PbFe_{1/2}Nb_{1/2}O_{3} (PFN) has been undertaken. Ferroelectric order occurs below 400 K, as evidenced by the softening with temperature and subsequent recovery of the…
We report on the microwave, terahertz (THz), infrared and Raman spectroscopic studies of $BiMn_{7}O_{12}$ ceramics, shedding more light into the nature of two structural phase transitions and their possible relation with ferroelectricity in…