Raman and Brillouin Scattering in Diamond. (9999)
The first order Raman line and the prominent features in the second order Raman spectrum of diamond crystals, interpreted on the basis of polarization selection rules and symmetry, provide energies...
P. Pavone, S. Baroni, Solid State Commun, J. C. Noya, C. P. Herrero, ...
11. The epitaxial film of the highly enriched 76 Ge isotope (average mass 75.63) was grown on an intrinsic Ge(111) substrate in an ultrahigh vacuum system (base pressure 10 �11 mbar) by molecular...
Doubly resonant Raman electron paramagnetic transitions of Cr3+ in ruby (Al2O3:Cr3+) (2009)
Lu, X., Venugopalan, S., Kim, H. J., Grimsditch, M., Rodriguez, S., Ramdas, A. K.
Lyman spectra of holes bound to Cu, Ag, and Au acceptors in ZnTe and CdTe (2009)
Chen, Gang, Miotkowski, I., Ramdas, A. K.
The group IB impurities (Cu, Ag, and Au) incorporated into II-VI zinc blende hosts of ZnTe and CdTe exhibit well resolved excitation lines followed by a photoionization continuum in their infrared...
Winter, A., Pascher, H., Krenn, H., Miotkowski, I., Ramdas, A. K.
The conduction-band spin splitting in Cd1-xFexTe bulk crystals is delineated on the basis of the Raman transitions manifested in coherent Stokes Raman scattering (CSRS). The independence at low...
Pekarek, T. M., Watson, E. M., Garner, J., Shand, P. M., Miotkowski, I., Ramdas, A. K.
Magnetic properties of single crystalline Ga1-xMnxS (x=0.09) have been measured near the spin-glass transition. No other III-VI DMS is currently known to exhibit a spin-glass transition for...
Alawadhi, H., Tsoi, S., Lu, X., Ramdas, A. K., Grimsditch, M., Cardona, M., ...
The temperature dependence of the A, B, and C excitons of ZnO, observed in modulated reflectivity spectra of (ZnO)-Zn-68-O-18 and (ZnO)-Zn-nat-O-nat in the range 10-400 K, reveal the superposition of...
Control of defect structure in compound semiconductors with stoichiometry: Oxygen in CdTe (2007)
Chen, G., Miotkowski, I., Rodriguez, S., Ramdas, A. K.
Two types of localized vibrational modes of oxygen substituting for Te in CdTe, i.e., O-Te, are reported. In one, O-Te is associated with a nearest neighbor (NN) vacancy as a (O-Te-V-Cd) center and...
Raman electron paramagnetic resonance in Zn1-xCrxTe and Cd1-xCrxTe (2007)
Lu, X., Tsoi, S., Miotkowski, I., Rodriguez, S., Ramdas, A. K., Alawadhi, H.
Raman electron paramagnetic resonance (Raman-EPR) of the transitions due to the spin flip of the 3d electrons of Cr+ in Zn1-xCrxTe and Cd1-xCrxTe is observed at h omega(PM)=g(Cr+)mu B-B with...
Raman scattering in the diluted magnetic semiconductor Zn1-xFexTe: A van Vleck paramagnet (2007)
Miotkowski, X. L. I., Ramdas, A. K., Rodriguez, S., Alawadhi, H., Pekarek, T. M.
Zn1-xFexTe, a zinc blende II-VI diluted magnetic semiconductor (DMS), exhibits a temperature independent magnetization at low temperature (van Vleck paramagnetism) as a consequence of the electronic...
Pekarek, T. M., Ranger, L. H., Miotkowski, I., Ramdas, A. K.
Magnetic properties of single-crystalline In1-xMnxSe (x=0.10) have been measured. A prominent thermal hysteresis in the magnetization is observed between 90 and 290 K. The magnetization is reversible...
Fe vibrational Spectroscopy of myoglobin and cytochrome f (2006)
Adams, K. L., Tsoi, S., Yan, J. S., Durbin, S. M., Ramdas, A. K., Cramer, W. A., ...
The Fe vibrational density of states (VDOS) has been determined for the heme proteins deoxymyoglobin, metmyoglobin, and cytochrome f in the oxidized and reduced states, using nuclear resonance...
Tracy, J. L., Mourad, R., Garner, J., Pekarek, T. M., Miotkowski, I., Ramdas, A. K.
Calculations and measurements of the magnetization of Ga1-xMnxS, a III-VI diluted magnetic semiconductor crystal, are reported. Results extend over a wide range of concentrations: x=0.18, 0.13,...
Stoichiometry driven impurity configurations in compound semiconductors (2006)
Chen, G., Miotkowski, I., Rodriguez, S., Ramdas, A. K.
Precise stoichiometry and departures therefrom in the composition of the tetrahedrally coordinated compound semiconductors allow impurity incorporation in more than one configuration. Ultrahigh...
Fe vibrational Spectroscopy of myoglobin and cytochrome f (2006)
Adams, K. L., Tsoi, S., Yan, J. S., Durbin, S. M., Ramdas, A. K., Cramer, W. A., ...
The Fe vibrational density of states (VDOS) has been determined for the heme proteins deoxymyoglobin, metmyoglobin, and cytochrome f in the oxidized and reduced states, using nuclear resonance...
Stoichiometry driven impurity configurations in compound semiconductors (2006)
Chen, G., Miotkowski, I., Rodriguez, S., Ramdas, A. K.
Precise stoichiometry and departures therefrom in the composition of the tetrahedrally coordinated compound semiconductors allow impurity incorporation in more than one configuration. Ultrahigh...
Pekarek, T. M., Ranger, L. H., Miotkowski, I., Ramdas, A. K.
Magnetic properties of single-crystalline In1-xMnxSe (x=0.10) have been measured. A prominent thermal hysteresis in the magnetization is observed between 90 and 290 K. The magnetization is reversible...
Tracy, J. L., Mourad, R., Garner, J., Pekarek, T. M., Miotkowski, I., Ramdas, A. K.
Calculations and measurements of the magnetization of Ga1-xMnxS, a III-VI diluted magnetic semiconductor crystal, are reported. Results extend over a wide range of concentrations: x=0.18, 0.13,...
Tracy, J. L., Mourad, R., Garner, J., Pekarek, T. M., Miotkowski, I., Ramdas, A. K.
Calculations and measurements of the magnetization of Ga1-xMnxS, a III-VI diluted magnetic semiconductor crystal, are reported. Results extend over a wide range of concentrations: x=0.18, 0.13,...
Isotopic-mass dependence of the A, B, and C excitonic band gaps in ZnO at low temperatures (2006)
Tsoi, S., Lu, X., Ramdas, A. K., Alawadhi, H., Grimsditch, M., Cardona, M., ...
Low temperature wavelength-modulated reflectivity measurements of isotopically engineered ZnO samples have yielded the dependence of their A, B, and C excitonic band gaps on the isotopic masses of Zn...
Capano, M. A., Kim, B. C., Smith, A. R., Kvam, E. P., Tsoi, S., Ramdas, A. K.
Cubic (3C) silicon carbide (SiC) epilayers grown on Si substrates by chemical vapor deposition, characterized using transmission electron microscopy (TEM), high-resolution x-ray diffraction (HRXRD),...
Pekarek, T. M., Ranger, L. H., Miotkowski, I., Ramdas, A. K.
Magnetic properties of single-crystalline In1-xMnxSe (x=0.10) have been measured. A prominent thermal hysteresis in the magnetization is observed between 90 and 290 K. The magnetization is reversible...
Isotopic-mass dependence of the A, B, and C excitonic band gaps in ZnO at low temperatures (2006)
Tsoi, S., Lu, X., Ramdas, A. K., Alawadhi, H., Grimsditch, M., Cardona, M., ...
Low temperature wavelength-modulated reflectivity measurements of isotopically engineered ZnO samples have yielded the dependence of their A, B, and C excitonic band gaps on the isotopic masses of Zn...
Tsoi, S., Miotkowski, I., Rodriguez, S., Ramdas, A. K., Alawadhi, H., Pekarek, T. M.
The Van Vleck paramagnetism of Cd1-xFexTe, a diluted magnetic semiconductor, is explored with electronic Raman spectroscopy of an internal transition of Fe2+, on the one hand, and the spin-flip Raman...
Tracy, J. L., Franzese, G., Byrd, A., Garner, J., Pekarek, T. M., Miotkowski, I., ...
The anisotropic magnetization of the III-VI diluted magnetic semiconductor (DMS), In1-xMnxS, is found within a mixed state model and compared to our measurements. The compound has a markedly...
Isotopic dependence of the E-0 ' and E-1 direct gaps in the electronic band structure of Si (2005)
Tsoi, S., Rodriguez, S., Ramdas, A. K., Ager, J. W., Riemann, H., Haller, E. E.
The E-0(') direct transition of Si between its valence band maximum (Gamma(8)(+)) and conduction band minimum (Gamma(6)(-)) and the E-1 direct transition along < 111 > are studied in...
Franzese, G., Byrd, A., Tracy, J. L., Garner, J., Pekarek, T. M., Miotkowski, I., ...
Results for the anisotropic magnetization of the III-VI diluted magnetic semiconductor (DMS), In1-xMnxS, are presented. The compound has a markedly different crystal structure from previously...
Pekarek, T. M., Arenas, D. J., Miotkowski, I., Ramdas, A. K.
Magnetic and transport properties of single-crystalline In1-xMnxSe (x=0.01 and 0.10) have been measured. In1-xMnxSe exhibits a prominent magnetization hysteresis between 90 and 290 K. In,-xMnxSe is...
Electronic band gaps of semiconductors as influenced by their isotopic composition (2005)
Ramdas, A. K., Rodriguez, S., Tsoi, S., Haller, E. E.
The present paper focuses on the renormalization effects of the band gaps in the electronic band structure of the elemental semiconductors traced to zero-point vibrations. Electron-phonon interaction...
Structure and energy gap of Cd1-xCaxTe and Cd1-yCaySe as a function of Ca2+ incorporation (2005)
Miotkowski, I., Alawadhi, H., Seong, M. J., Tsoi, S., Ramdas, A. K., Miotkowska, S.
Single crystals of Cd1-xCaxTe and Cd1-yCaySe ternaries, grown by the Bridgman technique and characterized by microprobe and x-ray techniques, showed the upper limit of x and y to be 0.05. The...
Franzese, G., Byrd, A., Tracy, J. L., Garner, J., Pekarek, T. M., Miotkowski, I., ...
Results for the anisotropic magnetization of the III-VI diluted magnetic semiconductor (DMS), In1-xMnxS, are presented. The compound has a markedly different crystal structure from previously...
Structure and energy gap of Cd1-xCaxTe and Cd1-yCaySe as a function of Ca2+ incorporation (2005)
Miotkowski, I., Alawadhi, H., Seong, M. J., Tsoi, S., Ramdas, A. K., Miotkowska, S.
Single crystals of Cd1-xCaxTe and Cd1-yCaySe ternaries, grown by the Bridgman technique and characterized by microprobe and x-ray techniques, showed the upper limit of x and y to be 0.05. The...
Pekarek, T. M., Arenas, D. J., Miotkowski, I., Ramdas, A. K.
Magnetic and transport properties of single-crystalline In1-xMnxSe (x=0.01 and 0.10) have been measured. In1-xMnxSe exhibits a prominent magnetization hysteresis between 90 and 290 K. In,-xMnxSe is...
Electronic band gaps of semiconductors as influenced by their isotopic composition (2005)
Ramdas, A. K., Rodriguez, S., Tsoi, S., Haller, E. E.
The present paper focuses on the renormalization effects of the band gaps in the electronic band structure of the elemental semiconductors traced to zero-point vibrations. Electron-phonon interaction...
Tracy, J. L., Franzese, G., Byrd, A., Garner, J., Pekarek, T. M., Miotkowski, I., ...
The anisotropic magnetization of the III-VI diluted magnetic semiconductor (DMS), In1-xMnxS, is found within a mixed state model and compared to our measurements. The compound has a markedly...
Tsoi, S., Miotkowski, I., Rodriguez, S., Ramdas, A. K., Alawadhi, H., Pekarek, T. M.
The Van Vleck paramagnetism of Cd1-xFexTe, a diluted magnetic semiconductor, is explored with electronic Raman spectroscopy of an internal transition of Fe2+, on the one hand, and the spin-flip Raman...
Isotopic dependence of the E-0 ' and E-1 direct gaps in the electronic band structure of Si (2005)
Tsoi, S., Rodriguez, S., Ramdas, A. K., Ager, J. W., Riemann, H., Haller, E. E.
The E-0(') direct transition of Si between its valence band maximum (Gamma(8)(+)) and conduction band minimum (Gamma(6)(-)) and the E-1 direct transition along < 111 > are studied in...
EFFECT OF UNIAXIAL STRESS ON THE EXCITATION SPECTRA OF DONORS IN SILICON, (2005)
When a uniaxial stress is applied to a multivalley semiconductor like silicon, the various conduction band minima shift in energy with respect to one another. Further, the site symmetry of a...
Pekarek, T. M., Arenas, D. J., Crooker, B. C., Miotkowski, I., Ramdas, A. K.
Magnetic measurements on the ferromagnetic behavior in the bulk II-VI diluted magnetic semiconductor Zn1-xCrxTe were made on two x=0.0033 single crystals taken from different regions of the same...
Broadened far-infrared absorption spectra for hydrated and dehydrated myoglobin (2004)
Zhang, C. F., Tarhan, E., Ramdas, A. K., Weiner, A. M., Durbin, S. M.
The far-infrared absorption spectra of myoglobin powder at hydration levels between 3.6 and 42 wt% were measured with terahertz time-domain spectroscopy and Fourier transform infrared spectroscopy....
Ibanez, J., Tarhan, E., Ramdas, A. K., Hernandez, S., Cusco, R., Artus, L., ...
The infrared transmission spectrum of Si-doped molecular beam epitaxy (MBE)-grown GaAs epilayers, 2-2.5-mum thick, measured in the oblique (Berreman) geometry, revealed distinct minima in p...
Tsoi, S., Alawadhi, H., Lu, X., Ager, J. W., Liao, C. Y., Riemann, H., ...
Photoluminescence and wavelength-modulated transmission spectra displaying phonon-assisted indirect excitonic transitions in isotopically enriched Si-28, Si-29, Si-30, as well as in natural Si, have...
Tsoi, S., Miotkowski, I., Rodriguez, S., Ramdas, A. K., Alawadhi, H., Pekarek, T. M.
Resonant enhancement enables the discovery and delineation of spin-flip Raman scattering (SFRS) from free or donor-bound electrons in diluted magnetic semiconductors containing 3d transition-metal...
Adams, K., Yan, J. S., Tsoi, S., Durbin, S., Ramdas, A. K., Cramer, W., ...
Tarhan, E., Miotkowski, I., Rodriguez, S., Ramdas, A. K.
The 3d-transition metal impurities (Mn, Co, and Cu) incorporated into III-V zinc blende hosts (GaAs, GaP, or InP) exhibit well resolved excitation lines followed by a photoionization continuum in...
Origin of the large band-gap bowing in highly mismatched semiconductor alloys (2003)
Wu, J., Walukiewicz, W., Yu, K. M., Ager, J. W., Haller, E. E., Miotkowski, I., ...
Photomodulated reflection, optical absorption, and photoluminescence spectroscopies have been used to measure the composition dependence of interband optical transitions in ZnSe1-xTex and ZnS1-xTex...
Wu, J., Walukiewicz, W., Yu, K. M., Shan, W., Ager, J. W., Haller, E. E., ...
Optical absorption experiments were performed using diamond-anvil cells to measure the hydrostatic pressure dependence of the fundamental bandgap of ZnSe1-xTex alloys over the entire composition...
QUANTITATIVE PIEZOSPECTROSCOPY OF THE GROUND AND EXCITED STATES OF ACCEPTORS IN SILICON. (1998)
Chandrasekhar, H. R., Fisher, P., Ramdas, A. K., Rodriguez, S.
On the polycrystalline forms of gypsum and their optical behaviour (1954)
Raman, C.V., Ramdas, A.K., Raman, C.V.
Scanned from Vol.4 of Scientific Papers of C.V. Raman. Ed. by S. Ramaseshan. Published in 1988 by the Indian Academy of Sciences, Bangalore.
The structure and optical behaviour of iridescent calcite (1954)
Raman, C.V., Ramdas, A.K., Raman, C.V.
Scanned from Vol.4 of Scientific Papers of C.V. Raman. Ed. by S. Ramaseshan. Published in 1988 by the Indian Academy of Sciences, Bangalore.
The infra-red absorption spectra of sodium chlorate and potassium chlorate crystals (1953)
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