Raman scattering study of (K$_x$Sr$_{1-x}$)Fe$_2$As$_2$ ($x$ = 0.0, 0.4) (2008)
Litvinchuk, A. P., Hadjiev, V. G., Iliev, M. N., Lv, Bing, Guloy, A. M., Chu, C. W.
Polarized Raman spectra of non-superconducting SrFe$_2$As$_2$ and superconducting K$_{0.4}$Sr$_{0.6}$Fe$_2$As$_2$ ($T_c = 37$ K) are reported. All four phonon modes (A$_{1g}$ + B$_{1g}$ + 2E$_g$)...
Raman phonons in ReOFeAs (Re= Sm, La) (2008)
Hadjiev, V. G., Iliev, M. N., Sasmal, K., Chu, C. W.
We report the polarized Raman spectra of undoped ReOFeAs (Re = Sm, La) collected at room temperature from $ab$ surfaces of impurity free microcrystals. The spectra exhibit sharp phonon lines on very...
Raman study of Twin Free YBa$_2$Cu$_3$O$_{6.5}$ (Ortho-II) Single Crystals (2008)
Iliev, M. N., Hadjiev, V. G., Jandl, S., Boeuf, D. Le, Popov, V. N., Bonn, D., ...
The polarized Raman scattering spectra from freshly cleaved $ab$, $ac$, and $bc$ surfaces of high quality twin free YBa$_2$Cu$_3$O$_{6.5}$ (Ortho-II) single crystals ($T_c$=57.5 K and $\Delta T =...
Origin of the Superconductivity in the Y-Sr-Ru-O and Y-Sr-Cu-O Systems (2007)
Galstyan, E., Xue, Y. Y., Iliev, M. N., Sun, Y., Chu, C. W.
We report on the structural, magnetic, and Raman-scattering studies of double perovskite structure Sr2Y(Ru1-xCux)O6-d systems made by systematic synthesis processes with various numbers of doping...
Distortion-Dependent Raman Spectra and Mode Mixing in RMnO3 Perovskites (2005)
Iliev, M. N., Abrashev, M. V., Laverdiere, J., Jandl, S., Gospodinov, M. M., ...
The polarized Raman spectra of orthorhombic RMnO3 series (R=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Y) were studied at room temperature. The variation of phonon frequencies with R ionic radius rR as a whole...
Epitaxial GaN Nanorods via Catalytic Capillary Condensation (2005)
Seo, H. W., Chen, Q. Y., Tu, L. W., Hsiao, C. L., Iliev, M. N., Chu, W. K.
Intrinsic catalytic process by capillary condensation of Ga-atoms into nanotrenches, formed among impinging islands during the wurzite-GaN thin film deposition, is shown to be an effective path to...
Characterizations of strain and defect free GaN nanorods on Si(111) substrates (2005)
Seo, H. W., Chen, Q. Y., Iliev, M. N., Chu, W. K., Tu, L. W., Hsiao, C. L., ...
GaN-nanorods grown on Si(111) substrates are found strain- and defect-free as characterized by micro Raman spectroscopy, secondary electron (SE) and cathode-luminescence (CL) imaging. The matrix...
Seo, H. W., Chen, Q. Y., Iliev, M. N., Kolev, N., Welp, U., Wang, C., ...
We have examined the effects of 20 keV electron irradiation on [-Cu(1)-O(1)-]n chain oxygen arrangements in oxygen deficient but otherwise twin-free YBa2Cu3O6+x single crystals. Comparison of...
Comparative Raman Studies of Sr2RuO4, Sr3Ru2O7 and Sr4Ru3O10 (2004)
Iliev, M. N., Popov, V. N., Litvinchuk, A. P., Abrashev, M. V., Backstrom, J., Sun, Y. Y., ...
The polarized Raman spectra of layered ruthenates of the Srn+1RunO3n+1 (n=1,2,3) Ruddlesden-Popper series were measured between 10 and 300 K. The phonon spectra of Sr3Ru2O7 and Sr4Ru3O10 confirmed...
Iliev, M. N., Lorenz, B., Litvinchuk, A. P., Sun, Y. Y., Chu, C. W.
Orthorhombic Y$_{1-x}$Ca$_x$MnO$_3$ ($0 \leq x \leq 0.5$) was prepared under high pressure and the variations with $x$ of its structural, magnetic, electrical properties and the polarized Raman...
Litvinchuk, A. P., Iliev, M. N., Pissas, M., Chu, C. W.
We report an infrared reflection spectroscopy study of La$_{1/2}$Ca$_{1/2}$MnO$_3$ over a broad frequency range and temperature interval which covers the transitions from the high temperature...
Litvinchuk, A. P., Iliev, M. N., Popov, V. N., Gospodinov, M. M.
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...
Phonons and Magnetic Excitations in Mott-Insulator LaTiO$_3$ (2003)
Iliev, M. N., Litvinchuk, A. P., Abrashev, M. V., Popov, V. N., Cmaidalka, J., Lorenz, B., ...
The polarized Raman spectra of stoichiometric LaTiO$_3$ (T$_N = 150$ K) were measured between 6 and 300 K. In contrast to earlier report on half-metallic LaTiO$_{3.02}$, neither strong background...
Temperature-Dependent Polarized Raman Spectra of CaFe2O4 (2003)
Kolev, N., Iliev, M. N., Popov, V. N., Gospodinov, M.
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...
Raman Phonons and Ageing-Related Surface Disorder in NaxCoO2 (2003)
Iliev, M. N., Litvinchuk, A. P., Meng, R. L., Sun, Y. Y., Cmaidalka, J., Chu, C. W.
The polarized Raman spectra from ab and ac surfaces of single crystal NaxCoO2 (x~0.7), parent compound of recently discovered superconductor NaxCoO2.yH2O, are reported and discussed. The crystals...
Iliev, M. N., Abrashev, M. V., Popov, V. N., Hadjiev, V. G.
The mixed-valence perovskitelike manganites are characterized by unique interrelation of Jahn-Teller distortions, electric and magnetic properties. The Jahn-Teller distortion follows the...
Carrier dynamics and infrared-active phonons in c-axis oriented RuSr$_2$GdCu$_2$O$_8$ film (2001)
Litvinchuk, A. P., Chen, S. Y., Iliev, M. N., Chen, C. L., Chu, C. W., Popov, V. N.
The conductivity spectra of c-axis oriented thin RuSr$_2$GdCu$_2$O$_8$ film on SrTiO$_3$ substrate, prepared by pulsed-laser deposition, are obtained from the analysis of the reflectivity spectra...