Study Of Relaxation Effects Research Articles

A study of relaxation effects in (1-x)BaZr0.2Ti0.8O3-xBa0.7Ca0.3TiO3 (x = 0.3, 0.35, 0.4) ferroelectric ceramics

Lead free (1-x)Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 (x = 0.3, 0.35, 0.4) ceramics were prepared via conventional two-step solid-state reaction technique. Temperature dependent dielectric measurements, conducted in the frequency range from 1 kHz to 1 MHz, indicate diffused phase transition for all the samples. The diffuseness of the transition has been studied by fitting the data with modified Curie-Weiss law. It is found that the composition with x = 0.3 behaves as a weak relaxor-ferroelectric, superposed by a non-relaxor behavior. Vogel-Fulcher law was used to characterize the relaxor-ferroelectric behavior while the analysis according to the Cole-Cole plots was used to characterize the non-relaxor features.

Effects of relaxation on hydrogen absorption in FeTi produced by ball-milling

Powders of FeTi ball milled with Pd were found to absorb hydrogen in the as-ball-milled state, without activation. This allows a study of relaxation effects on hydrogen absorption in nanocrystalline and amorphous FeTi. Hydrogen absorption characteristics (at room temperature) for powders in the unrelaxed state and after annealing were determined and compared with those for conventionally activated FeTi.

Studies of relaxation effects in the Coulomb gap

A new algorithm is described which is suitable for studying disordered localized systems with interactions. The algorithm is capable of finding the ground state and the low lying states of the system, in a classical approximation. Extension to quantum effects and possible applications to the study of various low-temperature properties are discussed. Results are reported of studies on the nature of low lying excitations, and on energy relaxation and dielectric relaxation at very low temperatures.

Study of relaxation effects in the 57Fe Mössbauer spectra of carbon-supported iron carbide particles

A modified model of relaxation for systems containing both a magnetic field and an electric field gradient is presented. This model is used to explain the 57Fe Mössbauer spectra of small iron χ-carbide particles supported on two types of high surface area carbon. On the basis of this model, it is concluded that χ-carbide particles interact weakly with graphitic carbon, but very strongly with nearly amorphous carbon. On the nearly amorphous carbon, the particles may, in fact, have an unusually high surface-to-volume ratio.

Study of relaxation effects in some aromatic polyesters by electret-thermal analysis

Relaxation transitions in polymers were examined by electret-thermal analysis. It was shown that maximum depolarization currents of electrets correspond to temperatures of releasing the mobility of individual structural elements of polymers. Two glass transition temperatures were established simultaneously for the first time in polyethylene terephthalate.

Study of relaxation effects behind shock fronts generated through plasma-flow interaction with large magnetic fields

Abstract Spectroscopic investigations of reflected luminous fronts, generated through plasma flow interactions with large magnetic fields show a gradual increase of electron density. Streak interferometric observation of a separate reflected shock front allows this to be interpreted as ionization relaxation. of a separate reflected shock front allows this to be interpreted as ionization relaxation.