Transparent ceramics have various potential applications such as infrared (IR) windows/domes, lamp envelopes, opto-electric components/devices, composite armors, and screens for smartphones and they can be used as host materials for solid-state lasers. Transparent ceramics were initially developed to replace single crystals because of their simple processing route, variability in composition, high yield productivity, and shape control, among other factors. Optical transparency is one of the most important properties of transparent ceramics. In order to achieve transparency, ceramics must have highly symmetric crystal structures; therefore, the majority of the transparent ceramics have cubic structures, while tetragonal and hexagonal structures have also been reported in the open literature. Moreover, the optical transparency of ceramics is determined by their purity and density; the production of high-purity ceramics requires high-purity starting materials, and the production of high-density ceramics requires sophisticated sintering techniques and optimized sintering aids. Furthermore, specific mechanical properties are required for some applications, such as window materials and composite armor. This review aims to summarize recent progress in the fabrication and application of various transparent ceramics.

Materials development and potential applications of transparent ceramics: A review

https://backend.orbit.dtu.dk/ws/files/234119008/20200527_Final_revised_manuscript_MPL_PCM_CEJ_no_Marks_1_.pdf

Recent advances and prospects of persistent luminescent materials as inner secondary self-luminous light source for photocatalytic applications

Synthesis, spectroscopic properties and applications of divalent lanthanides apart from Eu2+

Narrow Band Deep Red Photoluminescence of Y2Mg3Ge3O12:Mn4+,Li+ Inverse Garnet for High Power Phosphor Converted LEDs

A transparent 2 at% Nd3+-doped Lu3Al5O12 (LuAG) ceramic was fabricated by using tape-casting method and solid-state sintering technology. Based on the room temperature absorption spectrum, the three J–O intensity parameters were calculated with Judd–Ofelt analysis, and then, the radiative transition rates and branching ratios of transitions from 4 F 3/2 manifold to the ${}^4{{\rm {\mathbf I}}_{ \mathbf{{J}^{\prime}}}}$ ( $\mathbf{{ J}^{\prime}} = \ 13/2,\;11/2,\;9/2$ ) lower lying multiple manifolds were determined. The quantum efficiency of 80.4% was evaluated from the measured fluorescence lifetime and the radiative lifetime of the ${}^4{{\mathbf F}_{3/2\ }}$ manifold state. Also, the inter-Stark energy levels of the $4{{{\mathbf I}}_{\boldsymbol{J^{\prime}}}}$ manifolds were performed, and the peak emission cross sections of the ${}^4{\mathbf{F}_{3/2\ }} \to {}^4{{{\mathbf {I}}}_{\mathbf{{ J}^{\prime}}}}$ intermanifold transitions were determined. The total emission cross section for ${}^4{\mathbf{F}_{3/2\ }} \to $ ${}^4{\mathbf{I}_{9/2\ }}$ , ${}^4{\mathbf{I}_{11/2\ }}$ , and ${}^4{\mathbf{I}_{13/2\ }}$ transitions was calculated to be $7.41 \times {10^{ - 20}}\ {{\rm c}}{{{\rm m}}^2}$ , $29.83 \times {10^{ - 20}}\ {{\rm c}}{{{\rm m}}^2}$ , and $10.53 \times {10^{ - 20}}\ {{\rm c}}{{{\rm m}}^2}$ , respectively. Finally, under an 808 nm diode laser pumping, the continuous wave laser performances of the Nd:LuAG transparent ceramic were investigated.

Spectroscopic Properties and Continuous Wave Laser Performances at 1064 nm of Nd3+: LuAG Transparent Ceramic

In this study the densification behavior of LuAG:Nd (Lu 3− x Nd x Al 5 O 12 ) ceramics made by a combustion precursor was investigated. Precursor material synthesis was done according to a self combustion method and later calcined at different temperatures. Analysis of precursor materials was carried out by means of X-ray diffraction, TGA, dynamic light scattering and scanning electron microscopy. Green bodies were prepared by uniaxial and subsequently cold isostatic pressing. Green body densities were calculated by measurement of weight and dimensions. Ceramic bodies were sintered in a high temperature furnace for 4 h at 1700 °C in air atmosphere. Specimens were also analyzed by XRD and SEM. Additionally densities of specimens were determined using Archimedes method and the inline transmittance was measured at 1064 nm.

Towards the preparation of transparent LuAG:Nd3+ ceramics

From metals to nitrides - Syntheses and reaction details of binary rare earth systems

X-ray pure samples of SrBa8[BN2]6 and EuBa8[BN2]6 were synthesized from appropriate amounts of binary nitrides (Sr3N2, Ba3N2 and BN in sealed niobium ampoules and EuN, Ba3N2 and BN in BN crucibles, respectively) at temperatures up to 1370 K. The structure of SrBa8[BN2]6 was refined from single crystal X-ray diffractometer data: Fdm, a = 1595.1(1) pm, wR(F2) = 0.0515, 387 F2 values and 21 variables. EuBa8[BN2]6 has a lattice parameter of 1595.00(9) pm. Both nitridoborates adopt a new 2 × 2 × 2 superstructure variant of the LiCa4[BN2]3 type, realized through ordering of vacancies and Sr2+ and Eu2+ cations, respectively. The structures of SrBa8[BN2]6 and LiCa4[BN2]3 are related by a group–subgroup scheme. The Sr2+/vacancy ordering leads to an asymmetric coordination (1 × Sr2+ and 8 × Ba2+ in a distorted, mono-capped square prism) for the [BN2]3− units with B–N distances of 132 and 136 pm. Vibrational spectra of SrBa8[BN2]6 and EuBa8[BN2]6 confirm the discrete linear [BN2]3− units and 11B solid state MAS NMR spectra are compatible with single crystallographic sites for the boron atoms. In EuBa8[BN2]6 the spectra are profoundly influenced by interactions of the 11B nuclei with the unpaired electrons of the paramagnetic Eu2+ ions.

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Tobias Dierkes

Papers

Towards the preparation of transparent LuAG:Nd3+ ceramics

From metals to nitrides - Syntheses and reaction details of binary rare earth systems

Superstructure formation in SrBa8[BN2]6 and EuBa8[BN2]6.

An UV-C/B emitting Xe excimer discharge lamp comprising BaZrSi3O9 – A lamp performance and phosphor degradation analysis

On the energy transfer in (Y,Gd)Al3(BO3)4:Ln3+ (Ln = Tb3+, Dy3+)