Film thickness measurement with white light fringes

A method is described of measuring the thickness of thin films by using white light fringes obtained in a double pass Michelson interferometer. The method is suitable for the determination of thickness ranging from 15 nm to 2500 nm.     

Ionic conductivity of poly(2-vinyl pyridinium) salt in solid state

The preparation, characterization and conductivities of poly(2vinylpyridine), P-2VP and its fluoride derivative are reported here. The polymer P-2VP was prepared by thermal polymerization of 2vinylpyridine, 2VP and its salt, by acidification with HF. The formation of P-2VP salt was confirmed by IR and ¹H NMR techniques. Conductivities were determined from 30 to 110 °C in solid state. The addition of F⁻ ion increases the ionic conductivity of the polymer dramatically. The P-2VP-HF behaves as an intrinsic conducting polymer. The determination of the molecular mass of P-2VP and P-2VP-HF indicated that 95% of pyridine molecule was hydrofluorinated.     

Notes on the quantum theory of transition and time-dependent perturbation

It is shown that the introduction of the time-dependent perturbation sharply at an instant, is redundant to obtain the usual expression for the transition rates between states, provided the initial state is an incoherent mixture of the unperturbed states.     

Thomson scattering of high intensity beam with radiation reaction

The influence of radiation reaction on the intensity dependent effects in the scattering of a very intense directed monochromatic beam of light is investigated. It is shown that this has negligible effect on the frequency shift. The radiation reaction imparts a slow acceleration to the electron as a result of which there is a very weak “white radiation”. It also introduces relative phase lag between the different harmonic modes of vibration of the electron.     

On the resolvent kernel for the transfer problem in an homogeneous sphere

A scheme for obtaining the resolvent kernel of the integral equation for radiative transfer problems in an isotropically scattering sphere is proposed. Unlike the earlier attempts, the spherical problem is not transformed to its plane-parallel analogue.     

Investigation of levels in59Ni following the β+ decay of59Cu

82s⁵⁹Cu was produced by the⁵⁸Ni(p, γ)⁵⁹Cu reaction using enriched target. The γ-ray spectra following the gb⁺ decay of⁵⁹Cu were studied using two 65 cm³ and 55 cm³ Ge(Li) detectors. Besides confirming all the previously known γ-rays from⁵⁹Cu decay, new γ-rays have been observed and additional direct β⁺ branches to the 1778.8 and 1950keV states of⁵⁹Ni have been identified with estimated log/tft values of 5.6 and 6.7 respectively. Validity of some of the controversial levels around 1700 keV is discussed. The weak γ-ray branches from levels upto 1679.7 keV are compared and found to be in fair agreement with the theoretical predictions of Glaudemans et al.     

Determination of scandium and lanthanum in silicate rocks and coal with a simplified separation procedure and atomic absorption spectrometry

Simplified procedures for the quantitative separation and enrichment of scandium and lanthanum in igneous rocks are described. Co-precipitation with calcium oxalate is followed by co-precipitation with hydrated iron(III) oxide. Electrothermal and flame atomic absorption spectrometry are applied. The procedures are verified with synthetic sample solutions and the eighteen international reference samples of rocks and coal compare favourably with previously reported data and with data obtained by emission spectrography.     

Kramers-Kronig type of dispersion relation in nonlinear optics

The applicability of Kramers-Kronig (K-K) relation under nearly sharp resonant transition regime in narrow-gap semiconductors has been established and consequently, a generalized dispersion relation for nonlinear optical susceptibility of a dielectric is derived. This relation can be employed in the study of nonlinear optical processes in solids as well as in plasmas over a wide frequency spectrum.     

Growth of polystyrene films via gas‐phase polymerization with [Pd(CH3CN)4][BF4]2 thin film catalyst

The heterogeneous catalytic polymerization of styrene vapor with a tetrakis(acetonitrile)palladium(II) tetrafluoroborate, [Pd(CH₃CN)₄][BF₄]₂, thin film has been demonstrated. The catalyst is deposited by nebulization of dilute solutions onto a quartz crystal microbalance (QCM) and then exposed to styrene vapor in controlled environments. The use of QCM allows in situ monitoring of catalyst deposition and polymer growth kinetics. The polymerization process appears to involve the entire catalyst film rather than polymerization only at the catalyst film surface. The styrene vapor polymerization occurs rapidly after a short induction time needed for monomer dissolution and catalyst activation. The narrow molecular weight distribution of the produced polymer suggests that the deposited film acts as a single site catalyst. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1930–1934, 2005