Measurements of Defect Structures by Positron Annihilation Lifetime Spectroscopy of the Tellurite Glass 70TeO2-5XO-10P2O5-10ZnO-5PbF2 (X = Mg, Bi2, Ti) Doped with Ions of the Rare Earth Element Er3+

Abstract

The objective of the study was the structural analysis of the 70TeO2-5XO-10P2O5-10ZnO-5PbF2 (X = Mg, Bi2, Ti) tellurite glasses doped with ions of the rare-earth elements Er3+, based on the PALS (positron annihilation lifetime spectroscopy) method of measuring positron lifetimes. Values of positron lifetimes and the corresponding intensities may be connected with the sizes and number of structural defects, the sizes of which range from a few angstroms to a few dozen nanometers. Experimental positron lifetime spectrum revealed existence of two positron lifetime components τ 1 andτ 2. Their interpretation was based on two-state positron trapping model where the physical parameters are the positron annihilation rate and positron trapping rate.

Tellurite Glasses from the 70TeO2-5XO-10P2O5-10ZnO-5PbF2(X= Pb, Bi, Ti) System Doped Erbium Ions—The Influence of Erbium on the Structure and Physical Properties

“…In all the investigated tellurite glass systems, the third component τ 3 with a value above 1 ns was obtained. This has not been achieved in studies conducted so far [ 3 , 19 , 21 ]. Obtaining the third component was probably possible by increasing the amount of the admixture (twice).…”

“…Results of these measurements show that due to doping of tellurite glasses with erbium ions containing the optimal amount of erbium oxide (1200 ppm), it is possible to obtain the τ 3 component and its I 3 intensity, values related to the formation of ortho-positronium as well as the distribution of the density of the formation of free volumes. Notably, the research for the tellurite glasses presented in [ 21 ] could not obtain these values.…”

A review on optical bandgap engineering in TiO2nanostructures via doping and intrinsic vacancy modulation towards visible light applications

“…They studied the concentration of threedimensional vacancy clusters in nanocrystalline TiO 2 during annealing in the presence of O 2 and Ar. A number of defect state studies have been performed on different semiconductors such as ZnS [89], CdTe:Cl [90], CdZnTe:Ge [90], rare earth doped tellurite glasses [91], SrTiO 3 [92], GaN [93], SiC [94] and Group III nitrides [95]. The positron lifetime is proportional to the density of electrons at annihilation sites.…”

Fused Deposition Modeling 3D Printing: Test Platforms for Evaluating Post-Fabrication Chemical Modifications and In-Vitro Biological Properties

“…Scanning electron microscopy is an appropriate method for characterization of porosity and pore size of the surface of implants. Values of positron lifetimes and the corresponding intensities measured by positron annihilation lifetime spectroscopy may be connected with the size and the structural defects of implants [15].…”