Terahertz time‐domain spectroscopy has been used to study the optical and dielectric properties of three chalcogenide glasses: Ge30As8Ga2Se60, Ge35Ga5Se60, and Ge10As20S70. The absorption coefficients α(ν), complex refractive index n(ν), and complex dielectric constants ɛ(ν) were measured in a frequency range from 0.3 THz to 1.5 THz. The measured real refractive indices were fitted using a Sellmeier equation. The results show that the Sellmeier equation fits well with the data throughout the frequency range and imply that the phonon modes of glasses vary with the glass compositions. The theory of far‐infrared absorption in amorphous materials is used to analyze the results and to understand the differences in THz absorption among the sample glasses.

Lead zirconium titanate (PbZr 0.52 Ti 0.48 O 3 and PbZr 0.30 Ti 0.70 O 3 ) films were prepared on MgO (100) substrate by the sol-gel method. Film Thickness, microstructure and crystalline structure of the films were investigated by scanning electron microscope (SEM) and X-ray diffraction analysis, respectively. Terahertz time-domain spectroscopy has been used to investigate the dielectric properties of ferroelectric Pb(Zr, Ti)O 3 thin films in the frequency range of 0.2 to 2.0 THz.

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The structural evolution of mechanically alloyed Fe-C alloys was studied as a function of alloying times. The effect of alloying time on local structural changes of Fe-C has been investigated by means of Fe57 Mössbauer spectrometry, extended x-ray-absorption fine structure (EXAFS), and x-ray diffraction (XRD). XRD pattern from 24h alloyed Fe-C powder indicates at least the mixture of bcc-Fe and Fe3C phases. Mössbauer spectra analysis reveals that bcc-Fe decreases to the detriment of Fe3C phase with increasing alloying time, while both carbon-containing bcc-Fe and amorphouslike phase assigned to Fe located in grain boundaries (estimated at two atomic layers) remain alloying time independent. The variation of Fe3C phase content is in a good agreement with that observed by EXAFS analysis.