Infrared spectra of jennite and tobermorite from first-principles
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We present a MEMS infrared spectrometer for selective and quantitative chemical gas analysis. It contains a tunable optical filter of porous silicon that allows to measure the infrared absorption of a gas mixture at different wavelengths serially with only ...
In situ Fourier transform infrared absorption spectroscopy has been used to study the composition of particles formed and suspended in radio-frequency discharges of silane-oxygen-argon gas mixtures. The silane gas constumption was observed by infrared abso ...
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We present a far infrared gas spectrometer which uses a thin film pyroelectric detector integrated on silicon. The detector is in-house fabricated and consists of 1 x 50 elements of sol-gel deposited, zirconium rich lead titanate (PZT) which are suspended ...
Compressibility of MgCO3 is studied with infrared absorbance in the 100-1800 cm(-1) wave number range. Large values of the Gruneisen parameters for the translational modes, related to the optically active mode in the B1 structure, indicate that the pressur ...
An atomic infrared (IR) streak camera is demonstrated that operates in the mid- and far-infrared (lambda = 5-85 um), web beyond the long wavelength cutoff of conventional streak cameras. The temporal and spectral characteristics of the streak camera are de ...
Institute of Electrical and Electronics Engineers1998
Using a model structure consisting of a network of corner sharing tetrahedra, we calculate the infrared spectrum of amorphous SiO2 within a first-principles approach and find good agreement with experiment both for the positions and the intensities of the ...
The vibrational properties of amorphous SiO2 were studied within first-principles density functional theory. The calculated spectrum is in good agreement with neutron data, showing, in particular, a double peak in the high-frequency region. This doublet re ...
We report a first-principle study of the E(1) defect in alpha-quartz and of the analogous E'(gamma) defect in amorphous SiO2. Our calculation supports the attribution of both these defects to a positively charged oxygen vacancy. The ground-state configurat ...
The simulation and characterization of a low-cost IR source are described. The IR emission is obtained from heated thin film resistors which are either self- suspended or deposited an a membrane, The simulation, performed with a finite difference method, s ...