Structural, elastic and optical properties of zinc-alumino-borosilicate doped gadolinium oxide glass-ceramics
In recent years, researchers are developing a great interest towards the fabrication and synthesizing willemite (Zn2SiO4) glass-ceramics. However, intensity luminescence of willemite based glass ceramic doped with gadolinium oxide (Gd2O3) is less reported. Hence, this study is focusing on fabrica...
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| Format: | Thesis |
| Language: | English English |
| Published: |
2022
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/112697/1/112697.pdf |
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| Summary: | In recent years, researchers are developing a great interest towards the
fabrication and synthesizing willemite (Zn2SiO4) glass-ceramics. However,
intensity luminescence of willemite based glass ceramic doped with gadolinium
oxide (Gd2O3) is less reported. Hence, this study is focusing on fabricate and
synthesized willemite based glass-ceramics using Gd2O3 as dopant. The Gd2O3
doped zinc-alumino-borosilicate (ZnO-Al2O3-B2O3-SiO2) glass system were
synthesized via the melt-quenching approach using composition (60–x)ZnO–
5Al2O3–15B2O3–20SiO2:x(Gd2O3)(x = 0, 0.5, 1.0, 2.0 and 3.0 mol%) and
willemite-based glass-ceramics were obtained from these precursor glasses
through a controlled crystallization process.
According to all analysis, the best willemite based glass-ceramic has been
selected from the glass system when doped with 3 mol% of Gd2O3 and
temperature at 800 °C. XRD and FESEM methods were also used to analyze
the structural properties of precursor glass, the formation of willemite crystal
phase, shape, and size as crystallization temperatures increased. The average
approximated crystallite size determined by XRD is in the 50-70 nm range. The
structural properties of glass and glass-ceramics were assessed using FTIR
spectroscopy. The infrared spectra studies reveal the existence of SiO2 and ZnO4
vibrational groups indicating the establishment of the willemite crystal phase. As
for elastic analysis, the values for experimental elastic moduli were obtained from
ultrasonic velocities measurement by using the non-destructive ultrasonic
technique. The longitudinal and shear velocities vary from 4798 to 6976 m/s and
2991 to 3082 m/s, respectively. The experimental elastic moduli (longitudinal
modulus (L), shear modulus (G), bulk modulus (K) and Young’s modulus (E))
increases from 94.60 to 202.98 GPa, 36.77 to 39.61 GPa, 45.56 to 150.17 GPa
and 86.94 to 109.22 GPa, respectively. In addition, the optical band willemite
based glass-ceramics doped with Gd2O3 fluctuate from 3.64 to 3.38 eV due to
structural rearrangement of network. The emission spectra of gadolinium ions
show the strong emission peak at wavelengths of 425, 447, 462, 485, and 530
nm. The willemite phase shows prominent green emission spectra located at 530
nm. These emission spectra produce when the dopant content and heat
treatment temperatures increase, the luminescence performance of the glassceramics
also improves. The incorporation of gadolinium ions into the willemite
crystals as heat treatment temperatures increase affect the intensity of the
emission. The structural, elastic and optical properties of willemite glassceramics
enhanced with the addition of Gd2O3 as dopant. |
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