Solid-state Optical Materials and Luminescence Properties: On-Demand Oral Presentations
Sponsored by: ACerS Basic Science Division, ACerS Engineering Ceramics Division, ACerS Glass & Optical Materials Division
Program Organizers: Yiquan Wu, Alfred University; Jas Sanghera, Naval Research Laboratory; Akio Ikesue, World-Lab. Co., Ltd; Rong-Jun Xie, Xiamen University; Mathieu Allix, University of Orléans; Kiyoshi Shimamura, National Institute for Materials Science; Liangbi Su, Shanghai Institute of Ceramics; Dariusz Hreniak, Institute of Low Temperature and Structure Research

Friday 8:00 AM
October 22, 2021
Room: On-Demand Room 4
Location: MS&T On Demand

Invited
Comonomer Isomers Result in LWIR:Transmitting ORMOCHALC Polymers: Darryl Boyd¹; Vinh Nguyen¹; Frederic Kung²; Jason Myers¹; Daniel Gibson¹; Colin Baker¹; Woohong Kim¹; Jasbinder Sanghera¹; ¹US Naval Research Laboratory; ²University Research Foundation
    Inverse vulcanization is a method by which sulfur is combined with comonomer molecules to develop stable materials termed organically modified chalcogenide (ORMOCHALC) polymers. Although various comonomers have been used in the fabrication of ORMOCHALC polymers in prior studies, the reactions performed herein were used to determine the effect of using molecular isomers on the optical properties of ORMOCHALC polymers. This study specifically utilized the meta- and para- isomers of divinylbenzene (DVB) as comonomers to fabricate ORMOCHALC polymers. The use of these isomers resulted in polymers with notable differences in their optical properties, including the polymer colors, optical transmissions and refractive indices. Of great significance was the transmission of these ORMOCHALC polymers, which extended from the visible into the long-wave infrared region of the electromagnetic spectrum.

Invited
Enhancing Strength in Nanocrystalline Transparent Ceramics: Ricardo Castro¹; ¹University of California, Davis
    Transparent ceramics are subjected to mechanical and thermal stresses during application, requiring optimized microstructures to overcome engineering barriers. While transparent nanocrystalline ceramics offer interesting opportunities in the field as the transmitted light wavelength becomes larger than the grain size itself, controlling the mechanical properties at the nanoscale requires deep understanding of the impact of the extensive grain boundary region. In this talk we discuss the role of grain boundaries in controlling hardness and toughness of transparent nanocrystalline ceramics. Using samples prepared by High Pressure Spark Plasma Sintering and with grain sizes down to the 10nm range, we particularly point out the role of grain boundary composition on the macromechanics of the pellets. Magnesium and zinc aluminates are used as model materials as we reveal segregated ionic dopants and off-stoichiometry play key roles in the design of transparent nanoceramics with high strength.

Invited
A Green Chemistry Approach for the Preparation of Lanthanide Doped Alkaline-earth Fluoride Nanoparticles: Chiara Cressoni¹; Nicola Da Roit; Emil Milan¹; Francesca Parolini²; Mariapina D’Onofrio²; Giacomo Lucchini¹; Adolfo Speghini¹; ¹University of Verona and INSTM; ²University of Verona
    The luminescence of lanthanide ions activated alkaline-earth fluoride nanoparticles in the UV-Visible and near infrared (NIR) is of particular interest for biomedical applications, in particular for nanotheranostics. In this communication, we describe CaF2 or SrF2, nanoparticles (NPs), activated with luminescent lanthanide ions (Yb3+, Nd3+, Tm3+, Er3+), exhibiting efficient emission in the optical range. A “green chemistry” approach for their preparation has been considered, using a microwave assisted technique, permitting to prepare colloidal dispersion in aqueous media. By changing the experimental parameters, the features of the NPs can be properly tuned. We have investigated how the reaction temperature and time as well as the starting reagents concentration influence the NPs size. Preliminary results showed that the NPs size can be tuned from few to some tenths of nanometer, strongly influencing the luminescence properties. Biocompatibility of the prepared NPs have been determined by evaluating cell viability assays.

Invited
Seearching Nitride Luminescent Materials for Applications in High Luminance Lighting and Sensing: Rong-Jun Xie¹; ¹Xiamen University
    As a new type of luminescent materials, rare-earth-doped nitride phosphors play an indispensable role in InGaN LED-based solid-state lighting. With advances in solid state lighting, phosphors with desired properties are highly required to improve the optical quality of emissive devices. In addition, it is also a great mission to find applications other than lighting for nitride phosphors. In this presentation, we will introduce the design and applications of nitride phosphors for laser-driven lighting and stress sensing. Different searching methods for luminescent materials used in these two distinct fields will be presented.

Invited
Versatile Non-cubic Transparent Ceramics Applicable to Broad Wavelength Region: Ho Jin Ma¹; Do-Kyung Kim¹; ¹Korea Advanced Institute of Science & Tech
    Y₂O₃-MgO polycrystalline ceramics have been interested for infrared transparent ceramics due to their superior intrinsic optical and thermal characteristics. When the Y₂O₃-based nanocomposites are applied for infrared transparent ceramics, the large difference in refractive index between two phases brings about excessive grain boundary scattering, through which near-infrared transmittance decreases. Herein, pressure-assisted two-step consolidation of infrared transparent ceramics are investigated to achieve full density while retaining domain size. Transparency in short-wavelength region can be improved. To obtain broad mid-infrared transparency, the influence of additive is also studied. Furthermore, other non-cubic transparent ceramics are fabricated for applying NIR laser ceramics. Based on these results, we have demonstrated that the non-cubic transparent polycrystalline ceramics can be a promising candidate for use in broad infrared optical materials.

Micro- and Submicro-defects in Magneto-optical Crystal CeF3: Dongsheng Yuan¹; Encarnación G. Víllora²; Kiyoshi Shimamura²; ¹National Institte for Materials Science; ²NIMS
    CeF3 is a novel Faraday crystal to achieve UV-visible magneto-optical isolators, in particular for the working wavelengths below 400 nm. Although the CeF3 single crystals grown by the Bridgman technique had shown high crystalline and optical quality, however, residual scatterings are recently found inside. We have elucidated that these scattering centers are in fact microvoids with the shape of regular hexagons and sizes varying between 1 and 13 µm. Both theoretical simulation and spontaneous crystal growth indicate that these microvoids reflect exactly the natural crystal habit in “negative” form: the prisms stand along the c-axis and the hexagonal sides are parallel to the six equivalent planes perpendicular to the a-axis. The formation of the microvoids is possibly caused by the high vapor pressure of CeF3 melt at its high melting point. Meanwhile, the submicro-defects will be explored beyond the observed microvoids by using high-resolution XRD and TEM.

Effect of Samarium Doping on the Phase Stability and Optical Properties of Agro-food Waste-derived Calcium Silicates : Manmeet Kaur¹; Kulvir Singh¹; ¹SPMS, Thapar Institute of Engineering and Technology
    Rice husk ash and eggshell powder are used as sources of silica and calcium oxide to synthesize Ca_3-xSi₂O₇:xSm³⁺ (x (%) = 0.25, 0.50, 0.75, and 1.00)) via solid-state reaction method. X-ray diffraction results indicate that the Ca₃Si₂O₇ phase co-exists with the monoclinic-Ca₂SiO₄ phase. The effect of Sm³⁺ doping and stoichiometry on the volume fraction of the two phases is explored. SEM micrographs confirm the presence of two phases. Photoluminescence emission spectra contain characteristic emission peaks of Sm³⁺ and strong peaks due to the titanium ions, which are inherently found in agro-food wastes. Commission International de'Eclairage (CIE) coordinates lie in the green region, which is different from the CIE coordinates of Sm³⁺ doped samples derived from mineral oxides.