Hot isostatic pressing of transparent Yb3+-doped Lu2O3 ceramics for laser applications

Yb³⁺-doped Lu₂O₃ nanoparticles produced by laser ablation were used to fabricate transparent ceramics by a combination of pressureless sintering in vacuum (PS) followed by a hot isostatic pressing (HIPing). The samples were subjected to various PS and HIPing conditions and the microstructure evolution and its correlation with the transmittance were investigated. Relative densities of over 97% were achieved after PS at the temperatures of 1250–1700 °C. Rapid grain growth occurred within PS and HIPing temperatures above 1500 °C leading to formation of intragranular porosity which is deleterious for optical quality. Higher transmittance (81.7% at λ = 1080 nm) and ultrafine microstructure with an average grain size of 0.35 μm were obtained by PS at 1250 °C followed by HIPing at 1400 °C for 5 h under 207 MPa. Output power of 2.02 W with a slope efficiency of 46.5% was obtained under a quasi-continuous wave end pumping at 929.4 nm.     

Calculation and Experimental Determination of the Neutronics Characteristics of the IRT-T Research Reactor

Atomic Energy - The results of calculations and experimental determination of the neutronics characteristics of the IRT-T research reactor are presented. The IRT-T reactor is a pool reactor with...     

Separation of Samarium,Europium, and Gadolinium by Extraction with Organophosphorus Acids

Theoretical Foundations of Chemical Engineering - The features of distribution are studied and a complex technology for the separation of samarium, europium, and gadolinium is proposed. This...     

Magnetic Properties of Thin Epitaxial SiC Layers Grown by the Atom-Substitution Method on Single-Crystal Silicon Surfaces

Semiconductors - A cycle of experimental investigations is carried out, specifically, the measurements and analysis of field dependences of the static magnetic susceptibility in samples of...     

The structure and electrical properties of lithium doped pyrochlore Gd2Zr2O7

The lithium-doped phases Gd_1.7Li_0.3Zr₂O_6.7 and Gd₂Zr_1.7Li_0.3O_6.55 with a pyrochlore structure were prepared by the modified Pechini method using citric acid and glycerol. Monitoring of the lithium content by using a nuclear microanalysis showed that a significant loss of lithium occurred after heat treatment above 1200 °C. Dense ceramics with a stoichiometric lithium content can be prepared by a low temperature microwave sintering (1100 °C). The introduction of lithium in the Gd-sublattice was accompanied by a decrease in the unit cell parameter (a = 10.5208 (1) Å vs 10.5346 (2) Å for Gd₂Zr₂O₇) and during doping at the Zr-sites with lithium, the cell parameter increased (10.5720 (1) Å). The doping in both cases led to an increase in the free cell volume. The impedance spectroscopy results showed that the bulk conductivity can be enhanced by the Li⁺-doping at the Gd³⁺-site by almost an order of magnitude. The sample Gd₂Zr_1.7Li_0.3O_6.55 had a conductivity lower than that of Gd_1.7Li_0.3Zr₂O_6.7 due to the possible trapping of oxygen vacancies by a high-charged acceptor defect LiZr???. The conductivity?pO₂ measurements showed that the Li-containing phase was a pure oxide-ion conductor at T < 800 °C.     

Ultrasonic Assisted Nano-structures of Novel Organotin Supramolecular Coordination Polymers as Potent Antitumor Agents

Journal of Inorganic and Organometallic Polymers and Materials - The reaction of potassium tetracyanocupprate(I) with triethyltin bromide in presence of phenanthroline (Phen) and quinoxaline (Qox)...     

State of the Art and Prospects for Studies of Structure Formation in Extraction Systems with Metal Compounds

Theoretical Foundations of Chemical Engineering - The state of the art of studies in the field of structure formation in extraction systems with metal compounds is considered. Structure formation...     

Dielectric Measurements of Polymer Composite Based on CdS Quantum Dots in Low Density Polyethylene at Microwave Frequencies

Semiconductors - CdS nanoparticles (NPs) as quantum dots (QDs) added into low density polyethylene (LDPE) can significantly change the MW dielectric properties of the composites. Introducing into...     

Thermoelectric Properties of Nanocomposite Bi0.45Sb1.55Te2.985 Solid Solution with SiO2 Microparticles

Semiconductors - Nanocomposite thermoelectrics based on Bi0.45Sb1.55Te2.985 solid solution of p-type conductivity are fabricated by the hot pressing of nanopowders of this solid solution with the...     

Low-Temperature Annealing of Lightly Doped n-4H-SiC Layers after Irradiation with Fast Electrons

Semiconductors - The effect of low-temperature (up to 600°C) isothermal and isochronous annealing on the electrical characteristics of irradiated n-4H-SiC JBS Schottky diodes is studied....