Department of Magnetism

Group of infrared and millimeter wave spectroscopy



Members of the group:

  • Kurnosov V.S., Head of the group, Doctor of Sciences (Physics & Mathematics), Head of the Department;

  • Yeremenko A.V., Candidate of Sciences (Ph.D), senior researcher;

  • Tsapenko V.V., Candidate of Sciences (Ph.D), engineer.


The main field of research:


  • Mechanisms of the influence of magnetic ordering of a medium on the formation of its low-energy excitation spectrum.

  • Structural and magnetic phase transitions in multisublattice magnets.

  • Optical properties of frustrated magnetic structures.


Equipment:


    Experimental equipment allows to carry out investigation of absorption and reflection spectra in far infrared range of wavelengths. Temperature range extends from room to 4.2 K; magnetic fields are up to 30 kOe. FTIR spectrometer (0.02-0.2 mm) equipped with wide-temperature measurement cell (4.2-300 K) and superconducting solenoid (magnetic field up to 30 kOe).





The most important results:


  • Detection of one-phonon light absorption and scattering in crystals induced by the Brillouin zone reduction during magnetic ordering.

  • Detection of the phonon mechanism of antistockes excitation of a photoluminescence in CsMnCl3•2H2O single crystal with chain-like structure.

  • Detection of the resonance interaction between phonon modes from the center and boundary of the paramagnetic Brillouin zone in magnetically ordered phase of CsFeCl3•2H2O crystal.

  • Detection of the influence of a stripe charge ordering on the formation of spectra of phonons and magnons in low-dimensional nickelates.

  • Detection of two-magnon IR absorption in the cubic non-centrosymmetric multi-sublattice Cu2OSeO3 ferrimagnet, one of the rare materials with a "skyrmion" magnetic phase.

  • Detection in the IR spectra of ferroborates electronic transitions within ground state multiplet of rare earths induced by electron-phonon resonance interaction.