Low phonon energies and wideband optical windows of La2O3-Ga2O3 glasses prepared using an aerodynamic levitation technique

Kohei Yoshimoto,Atsunobu Masuno,Motoi Ueda,Tastunori Kawashima,Hiroyuki Inoue,Hiroshi Yamamoto

doi:10.1038/srep45600

Kohei Yoshimoto, Atsunobu Masuno + Show 4 more

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https://doi.org/10.1038/srep45600

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Abstract

xLa2O3-(100 − x)Ga2O3 binary glasses were synthesized by an aerodynamic levitation technique. The glass-forming region was found to be 20 ≤ x ≤ 57. The refractive indices were greater than 1.92 and increased linearly with increasing x. The polarizabilities of oxide ions were estimated to be 2.16–2.41 Å3, indicating that the glasses were highly ionic. The glasses were transparent over a very wide range from the ultraviolet to the mid-infrared region. The widest transparent window among the oxide glasses was from 270 nm to 10 μm at x = 55. From the Raman scattering spectra, a decrease in bridging oxide ions and an increase in non-bridging oxide ions were confirmed to occur with increasing La2O3 content. The maximum phonon energy was found to be approximately 650 cm−1, being one of the lowest among oxide glasses. These results show that La2O3-Ga2O3 binary glasses should be promising host materials for optical applications such as lenses, windows, and filters over a very wide wavelength range.

Highlights

XLa2O3-(100 − x)Ga2O3 binary glasses were synthesized by an aerodynamic levitation technique
This paper described the successful fabrication and fundamental properties of xLa2O3-(100 −x)Ga2O3 binary glasses
Evaluation using the Lorentz–Lorenz relation revealed that the polarizabilities of the oxide ions were as high as 2.16–2.41 Å3, indicating that the glasses were highly ionic

Summary

Introduction

XLa2O3-(100 − x)Ga2O3 binary glasses were synthesized by an aerodynamic levitation technique. The maximum phonon energy was found to be approximately 650 cm−1, being one of the lowest among oxide glasses These results show that La2O3-Ga2O3 binary glasses should be promising host materials for optical applications such as lenses, windows, and filters over a very wide wavelength range. Levitation techniques are useful to obtain bulk glasses by vitrification of materials with high melting temperatures and low glass-forming ability, such as rare-earth gallate binary gallate systems. Al2O3-11–15, TiO2-16–20, Nb2O5-21–23, and WO3-based[24] glasses without any network formers have been discovered using this method These “unconventional” glasses showed outstanding dielectric, optical, and mechanical properties as a result of the specific glass compositions and structures. Raman scattering spectra were taken for structural analysis and evaluation of phonon energies of the glasses

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