52 citations · 198 across the 16 of their papers we have counts for
16 papers
Electronic localization on the structural inhomogeneities formed due to Bi and Te deficiency in the MBE grown films of AFM topological insulator MnBi2Te4: Evidence from spectroscopic ellipsometry and infrared studies
N. N. Kovaleva, D. Chvostova, T. N. Fursova +7
The intrinsic substitutional and antisite defects cause unintentional doping and shift of the E_F position above the conduction band minimum in the AFM topological insulator (TI) M…
Bi layer properties in the Bi-FeNi GMR-type structures probed by spectroscopic ellipsometry
Natalia Kovaleva, Dagmar Chvostova, Ladislav Fekete +1
Bismuth (Bi) having a large atomic number is characterized by the strong spin-orbit coupling (SOC) and is a parent compound of many 3D topological insulators (TIs). The ultrathin B…
Bismuth layer properties in the ultrathin Bi-FeNi multilayer films probed by spectroscopic ellipsometry
N. N. Kovaleva, D. Chvostova, O. Pacherova +6
Using wide-band (0.5-6.5 eV) spectroscopic ellipsometry we study ultrathin [Bi(0.6-2.5 nm)-FeNi(0.8,1.2 nm)]N multilayer films grown by rf sputtering deposition, where the FeNi lay…
Localization Phenomena in Disordered Tantalum Films
Natalia Kovaleva, Dagmar Chvostova, A. Dejneka
Using dc transport and wide-band spectroscopic ellipsometry techniques we study localization phenomena in highly disordered metallic β-Ta films grown by rf sputtering deposition. T…
Localization effects in the disordered Ta interlayer of multilayer Ta-FeNi films: Evidence from dc transport and spectroscopic ellipsometry study
N. N. Kovaleva, D. Chvostova, O. Pacherova +4
Using dc transport and wide-band spectroscopic ellipsometry techniques, we study localization effects in the disordered metallic Ta interlayer of different thickness in the multila…
Symmetry breaking in single crystal SrTiO plates: EPR manifestations
Bulat F. Gabbasov, Irina N. Gracheva, Alexander A. Rodionov +6
Electron paramagnetic resonance studies of the impurity Fe and Mn centers indicate that the symmetry of the crystal structure of millimeter-scale strontium titanate p…
Control of Mooij correlations at the nanoscale in the disordered metallic Ta - nanoisland FeNi multilayers
N. N. Kovaleva, F. V. Kusmartsev, A. B. Mekhiya +12
Localisation phenomena in highly disordered metals close to the extreme conditions determined by the Mott-Ioffe-Regel (MIR) limit when the electron mean free path is approximately…
Efficient Green Emission from Edge States in Graphene Perforated by Nitrogen Plasma Treatment
N N Kovaleva, D Chvostova, Z Potůček +10
Plasma functionalization of graphene is one of the facile ways to tune its doping level without the need for wet chemicals making graphene photoluminescent. Microscopic corrugation…
Electronic Structure, Optical and Dielectric Spectroscopy Study of TbMnO3
V. A. Trepakov, A. G. Dejneka, O. E. Kvyatkovskii +6
Spectral ellipsometry studies of the optical functions, first observation of photoluminescence and low frequency dielectric permittivity investigations were performed in ferroelect…
Collective magnetic response of inhomogeneous nanoisland FeNi films around the percolation transition
N. N. Kovaleva, A. V. Bagdinov, A. Stupakov +6
By using superconducting quantum interference device (SQUID) magnetometry we investigated anisotropic high-field (H < 7 T) low-temperature (10 K) magnetization response of inhomoge…
Optical evidence of quantum rotor orbital excitations in orthorhombic manganites
N. N. Kovaleva, K. I. Kugel, Z. Potucek +8
In magnetic compounds with Jahn-Teller (JT) ions (such as Mn3+ or Cu2+), the ordering of the electron or hole orbitals is associated with cooperative lattice distortions. There the…
Anomalous multi-order Raman scattering in LaMnO_3: a signature of a quantum lattice effect in a Jahn-Teller crystal
N. N. Kovaleva, O. E. Kusmartseva, K. I. Kugel +8
The multi-order Raman scattering is studied up to a fourth order for a detwinned LaMnO_3 crystal. Based on a comprehensive data analysis of the polarisation-dependent Raman spectra…
d0 Ferromagnetic Interface Between Non-magnetic Perovskites
R. Oja, M. Tyunina, L. Yao +8
We use computational and experimental methods to study d0 ferromagnetism at a charge- imbalanced interface between two perovskites. In SrTiO3/KTaO3 superlattice calculations, the c…
EPR studies of manganese centers in SrTiO3: Non-Kramers Mn3+ ions and spin-spin coupled Mn4+ dimers
D. V. Azamat, A. Dejneka, J. Lancok +3
X- and Q-band electron paramagnetic resonance (EPR) study is reported on the SrTiO3 single crystals doped with 0.5-at.% MnO. EPR spectra originating from the S = 2 ground state of…
Experimental manifestations of the Nb^{4+}-O^{-} polaronic excitons in KTa_{0.988}Nb_{0.012}O_{3}
R. V. Yusupov, I. N. Gracheva, A. A. Rodionov +6
The formation of the photo-polaronic excitons in ABO_{3} perovskite type oxides has been detected experimentally by means of the photoinduced electron paramagnetic resonance studie…
Tensile strain induced changes in the optical spectra of SrTiO3 epitaxial thin films
A. Dejneka, M. Tyunina, J. Narkilahti +4
Effect of biaxial tensile strains on optical functions and band edge transitions of ultra thin epitaxial films was studied using as an example a 13 nm thick SrTiO3 films deposited…