Spectral characteristics of antimony-phosphate glass

Abstract

Determining the stable optimized compositions of the binary and ternary phases of antimony-phosphate glasses is the key issue. We prepare four series of glasses of the form (100- x)Sb2O3-xP2O5, where x = 30, 40, 50, 60 and 70 mol%, (95-x)Sb2O3-xP2O5-5MgO, where x = 60, 45, 40, 35, 30 and 25 mol%, (85-x)Sb2O3-xP2O5-15MgO, where x = 60, 45, 40, 35, 30 and 25 mol% and (75-x)Sb2O3-xP2O5-25MgO, where x = 60, 45, 40, 35, 30 and 25 mol% via conventional melt quenching method. Structural and optical properties of these glasses are determined through FTIR, UV-Vis and PL measurements. The XRD patterns confirm the amorphous nature of samples. The FTIR spectra of all prepared glass series recorded in the spectral ranges of 400 to 4000 cm-1 demonstrates the presence of asymmetric stretching vibrations of (PO3)2, Sb2O3 doubly degenerate stretching vibrations, stretching vibration of P–O–Sb linkages, vibration modes of SbO3 of the valentinite and vibration modes of SbO3 of the valentinite. The UV-Vis absorption spectra in the wavelength range of 200-2000 nm exhibit a broad transparency range with short wavelength absorption edge located at around 380 nm. A small shift of the absorption edge due to the change in glass composition is evidenced. The room temperature emission spectra under four different excitation wavelengths such as 300, 380, 550 and 780 nm display single sharp second harmonic emission peak at half wavelength and double frequency of the excitation wavelength. Glasses reveal low durability against humidity at higher P2O5 concentration exceeding 65 mol%. Furthermore, initiation of glass formation begins when Sb2O3 concentration is found to be less than or equal to 40 mol% for the binary system and 60 mol% for the ternary one. These promising features of the optical properties are highly useful for widespread photonic applications.