Electron spin resonance and optical characterization of defects in microcrystalline silicon (2008)
Vaněček, Milan, Poruba, A., Remeš, Z., Rosa, J., Kamba, S., Vorlíček, S., ...
Electron spin resonance (ESR), constant photocurrent method (CPM), photothermal deflection spectroscopy (PDS), Raman and IR spectroscopy have been used to measure microcrystalline silicon films....
Electron spin resonance and optical characterization of defects in microcrystalline silicon (2008)
Vaněček, Milan, Poruba, A., Remeš, Z., Rosa, J., Kamba, S., Vorlíček, S., ...
Electron spin resonance (ESR), constant photocurrent method (CPM), photothermal deflection spectroscopy (PDS), Raman and IR spectroscopy have been used to measure microcrystalline silicon films....
Kamba, S., Nuzhnyy, D., Nechache, R., Zaveta, K., Niznansky, D., Santava, E., ...
Infrared reflectance spectra of an epitaxial Bi2FeCrO6 thin film prepared by pulsed laser deposition on LaAlO3 substrate were recorded between 10 and 900 K. No evidence for a phase transition to the...
Kamba, S., Nuzhnyy, D., Veljko, S., Bovtun, V., Petzelt, J., Wang, Y. L., ...
Relaxor ferroelectric PbMg_1/3Ta_2/3O_3 ceramics and thin films were investigated by means of broad-band dielectric, time-domain terahertz (THz) and Fourier-transform infrared (IR) spectroscopy in...
Kamba, S., Nuzhnyy, D., Vanek, P., Savinov, M., Knizek, K., Shen, Z., ...
Infrared reflectivity and time-domain terahertz transmission spectra of EuTiO3 ceramics revealed a polar optic phonon at 6 - 300K, whose softening is fully responsible for the recently observed...
Quantum paraelectric behavior of pyrochlore PMN (2007)
Kamba, S., Nuzhnyy, D., Denisov, S., Veljko, S., Bovtun, V., Savinov, M., ...
Pb_1.83Mg_0.29Nb_1.71O_6.39 (PMN) crystallizing in a cubic pyrochlore structure exhibits, as the first dielectrics with pyrochlore structure, typical feature of quantum paraelectrics - its...
Kamba, S., Nuzhnyy, D., Savinov, M., Sebek, J., Petzelt, J., Prokleska, J., ...
BFO3 ceramics were investigated by means of infrared reflectivity and time domain THz transmission spectroscopy at temperatures 20 - 950 K, and the magnetodielectric effect was studied at 10 - 300 K,...
Ferroelectric Soft Modes in Ceramics and Films (2006)
Petzelt, J., Kamba, S., Hlinka, J.
Ferroelectric soft mode properties in ceramics and thin films are reviewed and compared with single crystals. In general, the permittivity in ceramics and thin films is markedly reduced compared to...
Petzelt, J., Zurmuhlen, R., Bell, A., Kamba, S., Kozlov, G. V., Volkov, A. A., ...
Five Ba(B'1/2B1/2'')O3 ceramic compounds (B' = Y3+, Gd3+, Nd3+, In3+; B'' = Ta and B' = Mg2+; B'' = W6+) have been prepared to investigate the origin of microwave losses. Infrared reflectivity and...
Far-infrared soft-mode behavior in PbSc1/2Ta1/2O3 thin films (2006)
Kamba, S., Berta, M., Kempa, M., Hlinka, J., Petzelt, J., Brinkman, K., ...
Temperature dependences of the optic phonons in PbSc1/2Ta1/2O3 (PST) sol-gel films deposited on sapphire substrates were studied by means of Fourier transform far-infrared transmission spectroscopy...
Dynamics of polar clusters in relaxor ferroelectrics (2006)
Kamba, S., Kempa, M., Berta, M., Petzelt, J., Brinkman, K., Setter, N.
The paper brings results of far infrared transmission studies of relaxor ferroelectric PbMg1/3Nb2/3O3 and PbSc1/2Ta1/2O3 thin films performed at temperatures between 10K and 900K. The spectra clearly...
Soft and central mode behaviour in PbMg1/3Nb2/3O3 relaxor ferroelectric (2006)
Kamba, S., Kempa, M., Bovtun, V., Petzelt, J., Brinkman, K., Setter, N.
The relaxor ferroelectric PbMg1/3Nb2/3O3 (PMN) is investigated by means of dielectric and Fourier transform far infrared transmission spectroscopy in ,the frequency range from 10 kHz to 15 THz at...
Anisotropic dielectric function in polar nano-regions of relaxor ferroelectrics (2005)
Hlinka, J., Ostapchuk, T., Noujni, D., Kamba, S., Petzelt, J.
The paper suggests to treat the infrared reflectivity spectra of single crystal perovskite relaxors as fine-grained ferroelectric ceramics: locally frozen polarization makes the dielectric function...
Far-infrared soft mode behavior in PST thin films (2005)
Kamba, S., Berta, M., Kempa, M., Petzelt, J., Brinkman, K., Setter, N.
Temperature dependences of the optic phonons in $\rm PbSc_{1/2}Ta_{1/2}O_3$ sol-gel films deposited on sapphire substrates were studied by means of Fourier transform far-infrared transmission...
Central mode and soft mode behavior in PbMg1/Nb2/3O3 relaxor ferroelectric (2004)
Kamba, S., Kempa, M., Bovtun, V., Petzelt, J., Brinkman, K., Setter, N.
The relaxor ferroelectric PbMg1/Nb2/3O3 was investigated by means of broad-band dielectric and Fourier Transform Infrared (FTIR) transmission spectroscopy in the frequency range from 1 MHz to 15 THz...
High-temperature phase transitions in SrBi_2Ta_2O_9 film: a study by THz spectroscopy (2004)
Kadlec, F., Kamba, S., Kuzel, P., Kadlec, C., Kroupa, J., Petzelt, J.
Time-domain THz transmission experiment was performed on a $\rm SrBi_2Ta_2O_9$ film deposited on sapphire substrate. Temperatures between 300 and 923 K were investigated and complex permittivity...
Dielectric spectra of a new relaxor ferroelectric system Ba2LnTi2Nb3O15 (Ln=La, Nd) (2004)
Kamba, S., Veljko, S., Kempa, M., Savinov, M., Bovtun, V., Vanek, P., ...
New relaxor ferroelectric system has been synthesized. BLTN exhibits a smeared maximum of permittivity, characteristic of classic relaxor behaviour, with a peak shift from 185 K at 100 Hz to 300 K at...
Lattice Dynamics in PMN (2004)
Prosandeev, S. A., Cockayne, E., Burton, B. P., Kamba, S., Petzelt, J., Yuzyuk, Yu., ...
Lattice dynamics for five ordered PMN supercells were calculated from first principles by the frozen phonon method. Maximal symmetries of all supercells are reduced by structural instabilities....
Temperature dependence of microwave and THz dielectric response in Srn+1TinO3n+1 (n=1-4) (2004)
Noujni, D., Kamba, S., Pashkin, A., Bovtun, V., Petzelt, J., Axelsson, A-K., ...
The microwave, near-millimetre and infrared (IR) dielectric response of Srn+1TinO3n+1 (n=1-4) Ruddlesden-Popper homologous series was studied in the temperature range 10 to 300 K. Remarkable...
Origin of the "Waterfall" Effect in Phonon Dispersion of Relaxor Perovskites (2003)
Hlinka, J., Kamba, S., Petzelt, J., Kulda, J., Randall, C. A., Zhang, S. J.
Inelastic neutron scattering study of the perovskite relaxor ferroelectric PZN:8%PT elucidates the origin of the previously reported unusual kink on the low frequency transverse phonon dispersion...