Measurements of defect structures by positron annihilation lifetime spectroscopy of the tellurite glass TeO2–P2O5–ZnO–LiNbO3 doped with ions of rare earth elements: Er3+, Nd3+ and Gd3+

• The structural analysis of tellurite glasses were examined by means of PALS.
• The tellurite glasses were doped with ions of the rare-earth elements (Er,Nd,Gd).
• The existence of two components τ1 and τ2 were found in the spectra of PALS.
• Determine the influence of dopant of ions of rare-earth on the structure of glasses.

The objective of the study was the structural analysis of the TeO2-P2O5-ZnO-LiNbO3 tellurite glasses doped with ions of the rare-earth elements: Er3+, Nd3+ and Gd3+ 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, such as vacancies, mono-vacancies, dislocations or pores, the sizes of which range from a few angstroms to a few dozen nanometres. Experimental positron lifetime spectrum revealed existence of two positron lifetime components τ1 and τ2. Their interpretation was based on two-state positron trapping model where the physical parameters are the annihilation velocity and positron trapping rate.

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