Structural, elastic and thermo-physical properties of Er2O3 nanoparticles doped bio-silicate borotellurite glasses

This paper presents a study on the structural, morphological and elastic properties of erbium oxide nanoparticles doped bio-silicate borotellurite glass system fabricated using the technique of melt-quenching with chemical compositional formula {[(TeO2)(0.7)-(B2O3)(0.3)](0.8)-(SiO2)(0.2)}(1-y) (Er2O3 NPs)(y) where 0.01 <= y <= 0.05. The objective of the work was to study the some elastic and thermal parameters associated with non-destructive ultrasonic technique, with the aim of utilizing the glasses for erbium doped fiber amplifier application. Various measurements and Characterizations techniques which includes density and molar volume measurements, energy dispersive X-ray fluorescence, X-ray diffraction (XRD), Fourier transform infrared (FTIR), Transmission electron microscopy and Pulse-echo technique were carried out in this study. The density values for the glasses increased from 4.1900 to 4.6003 gcm(-3) with the addition of 1-5% of Er2O3 NPs in the glass structure. The increase can be ascribed to increase in the overall molar weight of the glass due to incorporation of heavy Er3+ ions. The XRD patterns revealed no presence of sharp peaks with the observed broad hump around 2 theta = 20-30 degrees indicating the glassy and amorphous nature of the studied glasses. The FTIR spectra showed absorption with peaks around 1362-1385 cm(-1), 1221-1250 cm(-1), 655-689 cm(-1) and 602-630 cm(-1) wave number ranges, indicating the presences of H3BO3, SiO4, BO3, TeO3 and TeO4 structural units in the glass system. The microstructural nature observed in the glass morphology showed nanoparticle agglomerations in the glasses. The ultrasonic velocities, elastic moduli, microhardness, Poisson ratio, softening and Debye's temperatures, thermal expansion coefficient as well as other important parameters were calculated from the density and ultrasonic data. The values of the ultrasonic velocities, elastic moduli, Debye's temperature, softening temperature, thermal expansion coefficient and the acoustic impedance increased with increase in the Er2O3 NPs concentration.