The pH-dependent reactions in the sonochemical synthesis of luminescent fluorides: The quest for the formation of KYF crystal phases.

In this study Eu-doped yttrium fluorides were designed by ultrasound-assisted processes at different pH values (4.0-9.0).

Field-induced p-n transition in yttria-stabilized zirconia.

Oxide ion conducting yttria-stabilised zirconia ceramics show the onset of electronic conduction under a small bias voltage. Compositions with a high yttria content undergo a transition from p-type to n-type behavior at voltages in the range 2.4 to 10 V, which also depends on oxygen partial pressure.

From Complex Inorganic Oxides to Ag-Bi Nanoalloy: Synthesis by Femtosecond Laser Irradiation.

Bimetallic nanoalloys with a wide variety of structures and compositions have been fabricated through many diverse techniques. Generally, various steps and chemicals are involved in their fabrication. In this study, the synthesis of Ag-Bi nanoalloys by femtosecond laser irradiation of an inorganic oxide AgWO/NaBiO target without any chemicals like reducing agents or solvent is presented.

α-AgVO Decorated by Hydroxyapatite (Ca(PO)(OH)): Tuning Its Photoluminescence Emissions and Bactericidal Activity.

Defect-related luminescent materials have attracted interest because of their excellent optical properties and are considered as a less expensive and nontoxic alternative to commonly used lanthanide-based optical systems. These materials are fundamentally and technologically important for the next generation of full-color tunable light-emitting diodes as well as in the biomedical field. In this study, we report the preparation of α-silver vanadate (α-AgVO, AV) decorated by hydroxyapatite (Ca(PO)(OH), HA) with intense photoluminescence (PL) emissions at various HA/AV molar ratios (1:1-1:1/32) by a simple route based on chemical precipitation.

Tailoring the Bactericidal Activity of Ag Nanoparticles/α-AgWO Composite Induced by Electron Beam and Femtosecond Laser Irradiation: Integration of Experiment and Computational Modeling.

In nanotechnology research, significant effort is devoted to fabricating patterns of metallic nanoparticles on the surfaces of different semiconductors to find innovative materials with favorable characteristics, such as antimicrobial and photocatalytic properties, for novel applications. We present experimental and computational progress, involving a combined approach, on the antimicrobial activity against methicillin-resistant (MRSA) of as-synthesized α-AgWO samples and Ag nanoparticle composites (Ag NPs)/α-AgWO. The former included two morphologies: hexagonal rod-like (α-AgWO-R) and cuboid-like (α-AgWO-C), and the latter included composites formed under electron beam, Ag NPs/α-AgWO-RE and Ag NPs/α-AgWO-CE, and femtosecond (fs) laser irradiation, Ag NPs/α-AgWO-RL and Ag NPs/α-AgWO-CL.

Laser-induced formation of bismuth nanoparticles.

In the current communication, the synthesis of metallic Bi nanoparticles with coexisting crystallographic structures (rhombohedral, monoclinic, and cubic) obtained via direct femtosecond laser irradiation of NaBiO3 is demonstrated for the first time. By exploring the use of high laser power values, it is revealed that the promoted laser-mediated reactions lead to the synthesis of coexisting phases in metal nanoparticles, which may be a widely occurring phenomenon in other materials under femtosecond laser irradiation, and a fundamental concern for laser-based nanofabrication.

Towards the scale-up of the formation of nanoparticles on α-AgWO with bactericidal properties by femtosecond laser irradiation.

In recent years, complex nanocomposites formed by Ag nanoparticles coupled to an α-AgWO semiconductor network have emerged as promising bactericides, where the semiconductor attracts bacterial agents and Ag nanoparticles neutralize them. However, the production rate of such materials has been limited to transmission electron microscope processing, making it difficult to cross the barrier from basic research to real applications. The interaction between pulsed laser radiation and α-AgWO has revealed a new processing alternative to scale up the production of the nanocomposite resulting in a 32-fold improvement of bactericidal performance, and at the same time obtaining a new class of spherical AgWO nanoparticles.

Atmosphere- and Voltage-Dependent Electronic Conductivity of Oxide-Ion-Conducting ZrYO Ceramics.

Cubic, fluorite-structured solid solutions ZrYO (YSZ; x = 0.4-0.7) were prepared by sol-gel synthesis.

Theoretical and Experimental Insight on Ag2CrO4 Microcrystals: Synthesis, Characterization, and Photoluminescence Properties.

Ag2CrO4 microcrystals were synthesized by means of the coprecipitation method without the use of a surfactant under three different conditions. On the basis of the theoretical and experimental results, we describe the relationship among the structural order/disorder effects, morphology, and photoluminescence of the Ag2CrO4 microcrystals. The experimental results were correlated with the theoretical findings for a deeper understanding of the relationship between the electronic structure, morphology, and photoluminescence properties.

Spinel-rock salt transformation in LiCoMnO.

The transformation on heating LiCoMnO, with a spinel structure, to LiCoMnO, with a cation-disordered rock salt structure, accompanied by loss of 25% of the oxygen, has been followed using a combination of diffraction, microscopy and spectroscopy techniques. The transformation does not proceed by a topotactic mechanism, even though the spinel and rock salt phases have a similar, cubic close-packed oxygen sublattice. Instead, the transformation passes through two stages involving, first, precipitation of LiMnO, leaving behind a Li-deficient, Co-rich non-stoichiometric spinel and, second, rehomogenization of the two-phase assemblage, accompanied by additional oxygen loss, to give the homogeneous rock salt final product; a combination of electron energy loss spectroscopy and X-ray absorption near edge structure analyses showed oxidation states of Co and Mn in LiCoMnO.