El objetivo de este trabajo fue sintetizar matrices vítreas homogéneas basadas en óxido de silicio y óxidos alcalinos (litio, sodio y potasio) dopados con iones de tierras raras (Nd3 +, Sm3 +, Pr3 +) que sirvieron como sondas locales, para investigar el efecto de la densificación inducida por altas presiones (7.7 GPa) de estas matrices en propiedades estructurales y espectroscópicas. Para la caracterización estructural, se realizaron mediciones de espectroscopía de absorción infrarroja y Raman en los vidrios producidos revelando el efecto de cada ion alcalino en la matriz de sílice. Para evaluar el efecto de la densificación de alta presión en los vidrios, se realizaron mediciones espectroscópicas antes y después del procesamiento a 7,7 GPa. Fue posible observar cambios en el perfil de la banda vibratoria de la sílice alrededor de ~1050 cm-1 y ~1100 cm-1 en los espectros i...

Realiza el estudio de la caracterización estructural y espectroscópica de vitrocerámicos basados en vidrios teluretos dopados con Erbio con diferentes tiempos de tratamiento térmico, observando cristalización superficial por la técnica de DRx y su espectro.

In the present work the effect of alkali ions (Li, Na, K) and the combination of them on structural and spectroscopic properties of Nd3+ doped silicate glasses were systematically investigated. Results from infrared and Raman spectroscopy, as well as density and refractive index, were used to investigate the effect on the structural properties of the silicate glasses. Absorption and emission spectra of the glass samples were measured in the UV-VIS and NIR ranges. Relatively large, stimulated emission cross-section at 1.06 µm was obtained for samples containing a combination of alkali ions, especially with potassium. Moreover, the splitting induced by the Stark effect on the hypersensitive transition of Nd3+,4I9/2 ¿ 4G5/2, 2G7/2 was larger for the samples containing potassium, probably due to its larger ionic size. Judd-Ofelt theory was applied to evaluate the phenomenological intensity...

In the present work, the influence of alkali ions (Li, Na, K) on the structural and spectroscopic properties of silica glasses doped with Sm3+ was investigated. Infrared and Raman spectroscopy techniques were used to investigate the structural properties of the alkali silicate glasses. The optical absorption showed bands characteristic of Sm3+ ions in alkali silicate glasses, and this was investigated. The Judd–Ofelt theory was applied to evaluate the phenomenological intensity parameters (O2, O4, and O6) of the optical absorption measurements. The multi-channel visible and near infrared emission transitions originating from the 4G5/2-emitting state of the Sm3+ in alkali silicate glasses with a maximum phonon energy of ~1050 cm-1 were investigated. From the evaluated Judd–Ofelt parameters, radiative parameters such as spontaneous emission probabilities, radiative lifetimes, branching...