S. Mukamil’s research while affiliated with Abdul Wali Khan University Mardan and other places

In this work, the melt-quenching technique was employed to prepare lead borate glasses with varying amounts of Eu2O3. Various characterization approaches were used to investigate the physical, structural, optical, luminescence, and radiation-shielding properties of the developed glasses. The phase and structural compositions were confirmed by XRD and FTIR spectroscopy. It was found that as the Eu2O3 concentration increases, the density and refractive index also increase. The optical absorption spectra from 350 to 2300 cm−1 show five optical transitions in UV–Vis-NIR range. The absorption spectra results were used to calculate the direct and indirect bandgaps. The excitation spectra of photoluminescence found eight excitation bands in which the highest intensity transition was observed at 395-nm (7F0 → 5L6) under λemi = 613-nm. To study emission spectra, the 395-nm excitation wavelength was used. Five emissions bands at 578, 590, 613, and 700-nm were also evidenced. The highest intensity was recorded at 613 nm corresponding to 5D0 → 7F2 transition. The color coordinate (x, y) in the CIE diagram demonstrates the red–orange emission. The decay analysis demonstrates that when the Eu3+ content increases, the lifetime decreases. The shielding characteristics were observed in the energy range of 70–120 keV of X-ray. The HVL results at 120 keV revealed that these glasses provide greater shielding than commercial, concrete, red brick, and X-ray windows. Based on these observations, the fabricated glass can be used in numerous photonic applications such as illuminating and as a radiation shielding material.

The two phosphate glasses with composition ${{17{\rm K}}_2}{\rm O} {-} {{17{\rm Gd}}_2}{{\rm O}_3} {-} {{65{\rm P}}_2}{{\rm O}_5} {-} {{01{\rm Er}}_2}{{\rm O}_3}$ and ${{17{\rm KF} {-} 17{\rm Gd}}_2}{{\rm O}_3} {-}\def\LDeqbreak{} {{65{\rm P}}_2}{{\rm O}_5} {-} {{01{\rm Er}}_2}{{\rm O}_3}$ composition were synthesized by conventional-melt quenching techniques to study comparatively the spectroscopic, Judd–Ofelt (JO), radiative properties and NIR-luminescent properties. The Urbach energy of ${{\rm K}_2}{\rm O} {-} {\rm Er}$ and KF-Er samples was 0.3547 and 0.4799 eV. The observed trend is ${\Omega _2} \gt {\Omega _4} \gt {\Omega _6}$ and ${\Omega _2} \gt {\Omega _6} \gt {\Omega _4}$ for JO-intensity-parameters for ${{\rm K}_2}{\rm O} {-} {\rm Er}$ and KF-Er glasses. Moreover, ${{\rm K}_2}{\rm O} {-} {\rm Er}$ has higher ${\Omega _4}$ and ${\Omega _6}$ values, thus having more rigidity and viscosity than KF-Er. The measured values of full-width-half-maximum (FWHM) for ${{\rm K}_2}{\rm O} {-} {\rm Er}$ and KF-Er glasses 54.60 and 58.27, respectively. The measured values of FWHM for ${{\rm K}_2}{\rm O} {-} {\rm Er}$ and KF-Er glasses were 54.60 and 58.27, respectively. The ${{A}_R}$ values are 417.61 and 3038 for ${{\rm K}_2}{\rm O} {-} {\rm Er}$ and KF-Er glasses, respectively. The radiative lifetime ( ${\tau _R}$ ) for ${{\rm K}_2}{\rm O} {-} {\rm Er}$ and KF-Er glasses is 2.39 ms and 3.18 ms, respectively. Utilizing McCumber theory the ${G}\;(\lambda ,\;\beta)$ is positive and population-inversion is more than 0.4 for both glasses. Both samples have flat gain-bandwidth in the range of 1505–1585 nm, which covers the S-, C-, and L-bands of the low-loss optical communication-window. It is evident from all these results that the prepared glass samples have the potential for a low-threshold and high gain NIR laser and optical-fiber amplifier.

The present study aims to examine the concentration effect of Eu3+ ions in Boro Tellurite glass and how it affects its physicochemical and photo luminescent characteristics. Using the melt quenching method, a series of Boro-Telluride glasses with the composition (30-x) TeO2–30B2O3–10ZnO–30BaO–xEu2O3 (where x = 0.00, 0.05, 0.10, 0.50, 1.00, 1.50, 2.00, and 2.50 mol%) were synthesized. The results of the XRD analysis revealed that the prepared samples are amorphous. As the concentration of the Eu2O3 increases, the density and refractive index rise, but the molar volume decreases, indicating that the glass matrix has become more compact. Similarly, the absorption spectra and oscillator strength calculated with JO theory demonstrate the transition from 7F0 to 5L6 (in the UV–Vis region) and 7F0 to 5L6 (in the NIR region) is more intense. For TBZB–Eu7 glass, the phonon sideband energy is estimated to be 717 cm−1 and compared with the BGO scintillator, the integrated scintillation efficiency is estimated to be 16.14%. These findings demonstrate that the current glasses doped with 2 mol% Eu3+ exhibit strong luminescence qualities and can be used for portal imaging systems (MeV energies) non-destructive analysis such as industrial and medical X-ray imaging systems, and also have potential for laser application.

(Li2O)0.20(SrO)0.30(Nd2O3)0.01(B2O3)0.49−x(Gd2O3)x, where x = 0, 3, 5, 7, and 10 mol%, glass was melt-quenched to test it as a laser source in the near-infrared (NIR) region. The structural modification, absorption spectra, Judd–Ofelt (J–O) parameters, luminescence spectra, radiative laser parameters, lifetimes, XRD, and FTIR spectra were studied. Luminescence spectra excited at λexc = 584 nm revealed the highest intensity peak at 1073 nm due to the transition of ⁴F3/2 → ⁴I11/2. An important phenomenon of concentration quenching was observed and optimized luminescence was achieved with the sample having the concentration x = 07 mol%. The lifetimes of the donor and acceptor and energy transfer from gadolinium to neodymium were obtained from the luminescence decay kinetics. The findings show that Nd-doped Gd2O3-modified glass materials have potential as NIR laser sources.