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141.
K. Ramamoorthy M. Jayachandran K. Sankaranarayanan Pankaj Misra L. M. Kukreja C. Sanjeeviraja 《Current Applied Physics》2004,4(6):679-684
Intrinsic epitaxial zinc oxide (epi-ZnO) thin films were grown by laser-molecular beam epitaxy (L-MBE), i.e., pulsed laser deposition (PLD) technique using Johnson Matthey “specpure”-grade ZnO pellets. The effects of substrate temperatures on ZnO thin film growth, electrical conductivity (σ), mobility (μ) and carrier concentration (n) were studied. As well as the feasibility of developing high quality conducting oxide thin films was also studied simultaneously. The highest conductivity was found for optimized epi-ZnO thin films is σ=0.06×103 ohm−1 cm−1 (n-type) (which is almost at the edge of semiconductivity range), carrier density n=0.316×1019 cm−3 and mobility μ=98 cm2/V s. The electrical studies further confirmed the semiconductor characteristics of epi-n-ZnO thin films. The relationship between the optical and electrical properties were also graphically enumerated. The electrical parameter values for the films were calculated, graphically enumerated and tabulated. As a novelty point of view, we have concluded that without doping and annealing, we have obtained optimum electrical conductivity with high optical transparency (95%) for as deposited ZnO thin films using PLD. Also, this is the first time that we have applied PLD made ZnO thin films to iso-, hetero-semiconductor–insulator–semiconductor (SIS) type solar cells as transparent conducting oxide (TCO) window layer. We hope that surely these data be helpful either as a scientific or technical basis in the semiconductor processing. 相似文献
142.
Paramagnetic resonance in a free radical, Diphenyl-Picryl-Hydrazyl, has been studied and the results are compared with those of other workers. Low temperature work indicated that the transition from paramagnetic to antiferromagnetic state should occur at 1° K. 相似文献
143.
Ohne Zusammenfassung 相似文献
144.
Shyam Sunder Misra 《中国化学会会志》1977,24(2):87-90
Thirteen phenanthryl and biphenylyl chalcones have been synthesized in presence of saturated solution of Na in methanol to evaluate their germicidal activity against gram +ve and ?ve bacteria. 相似文献
145.
Gwal A. K. Misra K. D. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1977,5(3):146-150
Mode conversion and collisionless absorption of electromagnetic wave at the cyclotron harmonic frequencies in an inhomogeneous non-Maxwellian magnetoplasma have been studied. Under suitable energy transfer condition the converted electrostatic wave (plasma wave) either grows or damps. The expressions for the growth/damping rates of this wave have been derived and studied at the cyclotron harmonic frequencies. The effect of the temperature anisotropy on the growth/damping rate of the electrostatic wave at the second cyclotron harmonic frequency has been shown. Growth of such electrostatic waves at ionospheric heights may explain the observed upper hybrid resonance (UHR) echoes and noise bands at the second cyclotron harmonic frequency. 相似文献
146.
S. K. Misra M. Kahrizi K. Singh N. Venkatramani D. Bahadur 《Journal of magnetism and magnetic materials》1995,150(3):430-436
Mechanical alloying (MA) technique has been used to synthesize metastable alloys with nominal compositions Ti2Fe (MA for 1, 5, and 26 h), Al65Cu20Fe15 (MA for 26 and 34 h) and Al40Cu10Mn25Ge25 (MA for 42 h). These have been studied by EPR, X-ray diffraction, differential thermal analysis (Ti2Fe only), and magnetization (Ti2Fe only) techniques. X-ray diffraction provided information on transformation to metastable phases, while the EPR spectra gave insight into inequivalent paramagnetic transition metal sites in the alloys and the temperature variation of magnetic ordering of the samples. Magnetization data on Ti2Fe system has been interpreted in terms of phase separations within the amorphous phase. It is concluded that MA process significantly influences the magnetic properties of the samples, wherein the duration of MA process plays an important role. The EPR and magnetization data indicate that the disorder of paramagnetic ions within the samples increases with increasing temperature. 相似文献
147.
Dielectric studies in dilute solutions of cyclohexane and benzene have been carried out in the temperature range 294–318°K.
The observed data have been utilized to evaluate the relaxation times and thermodynamic parameters of these molecules. The
high values ofα for 2-acetyl pyridine indicate the occurrence of more than one relaxation time. In the remaining systems, the observed lowα values indicate their rigid behaviour. The variation in the dielectric relaxation time is mostly correlated with the change
in the heterocyclic configuration of the system. 相似文献
148.
We derive an approximate formula for the quark mass in ξ-formalism. Using the QCD-based form of structure function, we analyse
the SLAC-MIT data to estimate the experimentally allowed ranges of quark mass. The possible variation of our results with
QCD cut-off parameter, gluon distribution, hard intrinsic charm component of the proton wavefunction and the higher twist
effects are also discussed. 相似文献
149.
Ioannis E. Antoniou Baydyanath Misra 《International Journal of Theoretical Physics》1992,31(1):119-136
We construct a self-adjoint time operator for massless relativistic systems in terms of the generators of the Poincaré group. The Lie algebra generated by the time operator and the generators of the Poincaré group turns out to be an infinitedimensional extension of the Poincaré algebra. The internal time operator generates two new entities, namely the velocity operator and the internal position operator. The transformation properties of the internal time and position operator under Lorentz boosts are different from what one would expect from relativity theory. This difference reflects the fact that the time concept associated with the internal time operator is radically different from the time coordinate of Minkowski space, due to the nonlocality of the time operator. The spectral projections of the time operator allow us to construct incoming subspaces for the wave equation without invoking Huygens' principle, as in two and one spatial dimensions where Huygens' principle does not hold. 相似文献
150.
L K Misra M G Luthra S R Amtey G Elizondo-Riojas S H Swezey L E Todd 《Magnetic resonance imaging》1984,2(1):33-35
Proton spin-lattice relaxation times (T1) of pectoralis major muscles from normal (Line 412) and homozygous dystrophic (Line 413) chicks was measured by FONAR QED 80 at 1.69 MHz. The T1 values of dystrophic muscles (216.8 +/- 17.3 ms) was two-fold higher than those of normal muscles (110.2 +/- 8.1 msec). When these values were compared with the T1 values obtained at high frequencies (20 MHz and 32 MHz), the T1 differentiation between normal and dystrophic muscles was considerably enhanced at 1.69 MHz. Based on these results, we suggest that the high resolution of T1 obtained at low frequency (1.69 MHz) could be effectively used to detect the degenerative processes in muscles by the NMR techniques. 相似文献