Related papers: Polar modes in multiferroic Ba_2Mg_2Fe_(12)O_(22) …
Numerous applications of hexagonal ferrites are related to their easy axis or easy plane magnetocrystalline anisotropy configurations. Certain W-type ferrites undergo spin reorientation transitions (SRT) between different anisotropy states…
Magnetic dc susceptibility between 1.5 and 800 K, ac susceptibility and magnetization, thermodynamic properties, temperature dependence of radio and audio-wave dielectric constants and conductivity, contact-free dielectric constants at…
Infrared reflection and transmission as a function of temperature have been measured on single crystals of Cu$_{3}$Bi(SeO$_{3}$)$_{2}$O$_{2}$Cl. The complex dielectric function and optical properties along all three principal axes of the…
The spin-phonon coupling in magnetic materials is due to the modulation of the exchange integral by lattice vibrations. BaFe12O19 M-type hexaferrite, which is the most used magnetic material as permanent magnet, transforms into ferromagnet…
We report the temperature dependent THz to mid-infrared response of hexagonal-ErMnO3 using absorption, reflectivity, and emissivity techniques from 2 K to 1700 K. At low temperatures, lowest frequency vibrational modes coexist with…
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…
Infrared reflectance of alpha'-NaV2O5 single crystals in the frequency range from 50 cm-1 to 10000 cm-1 was studied for a, b and c-polarisations. In addition to phonon modes identification, for the a-polarised spectrum a broad continuum…
We investigated the far- and mid-infrared reflectivity (20-6000 wavenumber) of several pure and doped CuGeO3 single crystals. The b-axis and c-axis optical response is presented for different temperatures between 4 K and 300 K. Moreover, a…
The optical properties of magnetite at room temperature were studied by infrared reflectivity measurements as a function of pressure up to 8 GPa. The optical conductivity spectrum consists of a Drude term, two sharp phonon modes, a…
Magnetic and dielectric properties of the hexagonal triangular lattice antiferromagnet 2H-AgFeO2 have been studied by neutron diffraction, magnetic susceptibility, specific heat, pyroelectric current, and dielectric constant measurements.…
The chiral langasite Ba$\_3$NbFe$\_3$Si$\_2$O$\_{14}$ is a multiferroic compound. While its magnetic order below T$\_N$=27 K is now well characterised, its polar order is still controversial. We thus looked at the phonon spectrum and its…
The lattice dynamics of Ba$_2$CuGe$_2$O$_7$, a compound which develops Dzyaloshinsky-Moriya (DM) helical magnetism below $T_N$ = 3.2 K, has been studied by measuring the infrared reflectivity of a single crystal with the radiation polarized…
Polarized Raman spectra of the epitaxial Ba0.5Sr0.5TiO3 film, bi-color BaTiO3/Ba0.5Sr0.5TiO3 superlattice, and tri-color BaTiO3/Ba0.5Sr0.5TiO3/SrTiO3 superlattice were studied in a broad temperature range of 80-700 K. Based on the…
Our measured dielectric constant and mechanical response of multiferroic BiFeO3 indicate four phase transitions below room temperature. Features correlate with those reported at 50K (from a peak in the zero-field-cooled magnetic…
By employing resonant X-ray microdiffraction, we image the magnetisation and magnetic polarity domains of the Y-type hexaferrite Ba$_{0.5}$Sr$_{1.5}$Mg$_2$Fe$_{12}$O$_{22}$. We show that the magnetic polarity domain structure can be…
The Raman spectra of CaFe2O4 were measured with several exact scattering configurations between 20 and 520K and the symmetry of all observed Raman lines was determined. The Ag and B2g lines were assigned to definite phonon modes by…
Polarization dependent vanadium L edge X-ray absorption spectra of BaVS$_3$ single crystals are measured in the four phases of the compound. The difference between signals with the polarization \textbf{E}$\perp$\textbf{c} and…
Optical properties of single-crystal monoclinic CuO in the range 70 - 6000 \cm were studied at temperatures from 7 to 300 K. Normal reflection spectra were obtained from the (001) and (010) crystal faces thus giving for the first time…
We study experimentally and theoretically optical absorption spectra of neodymium ferroborate in the temperature range $6-32$ K. We show that the temperature dependences of integral intensities of absorption lines demonstrate qualitatively…
Mutual control of the electricity and magnetism in terms of magnetic (H) and electric (E) fields, the magnetoelectric (ME) effect, offers versatile low power-consumption alternatives to current data storage, logic gate, and spintronic…