Oxygen mobility in RBa2Cu3O6+x by anelastic relaxation.

Anelastic Relaxation of Metallic Glasses

Anelastic relaxation processes due oxygen in Nb–3.1 at.% Ti alloys

In the last 50 years several studies have been made to understand the relaxation mechanisms of the heavy interstitial atoms present in transition metals and their alloys. Internal friction measurements have been carried out in a Nb–Ti alloy containing 3.1 at.% of Ti produced by the Materials Department of Chemical Engineering Faculty of Lorena (Brazil), with several quantities of oxygen in soli...

Anelastic Relaxation of Protonic Defects in M3+-Doped BaCeO3

When perovskite-structured BaCe03 is doped with M ~ + ions (e.g., ~ d ~ + , Gd3+,yb33 that substitute on ce4+ sites, oxygen-ion vacancies are created for charge compensation. However, when treated in water vapor, the vacancies are replaced by protons, which take the form of OH' ions. This treatment makes the materials a good protonic conductor. Questions about the defect structure of the proton...

Anelastic and Compressible Simulations of Stellar Oxygen Burning

In this paper we compare fully compressible (Meakin & Arnett 2006a,b) and anelastic (Kuhlen, Woosley, & Glatzmaier 2003) simulations of stellar oxygen shell burning. It is found that the two models are in agreement in terms of the velocity scale (vc ∼ 10 7 cm/s) and thermodynamic fluctuation amplitudes (e.g., ρ/〈ρ〉 ∼ 2 × 10) in the convective flow. Large fluctuations (∼11%) arise in the compres...

Anelastic and Dielectric Relaxation Measurements in the Protonic Conductor Ba3(Ca1.18Nb1.82)O9-

In order to study the local proton motion in complex perovskite-type protonic conductors anelastic and dielectric relaxation measurements have been carried out at the compound Ba3(Ca1.18Nb182) 09.&. Both techniques show spectra depending on the proton concentration. From the dielectric measurements an activation energy of E, = 0.5 eV for the local reorientation of a proton-related defect can be...