A review: X-ray excited luminescence of gadolinium based optoelectronic phosphors.

X-ray excited fluorescence tomography is an emerging field in the application of bio-imaging and computer tomography. Some rare-earth doped inorganic phosphors like gadolinium oxide (Gd2 O3 ), yttrium oxide (Y2 O3 ), zinc tungstate (ZnWO4 ), cesium fluoride (CsF), barium fluorochloride (BaFCl), lanthanum oxybromide (LaOBr) are shown outstanding applications for X-ray excited phosphors. Gadolinium (Gd)-based inorganic phosphors show extraordinary applications in the field of X-ray chromatography and computer chromatography. In this review article, we discussed the general information about X-ray excited luminescence (XEL) phosphor. Further, we discussed importance, synthesis, structural and photoluminescence (PL) properties of rare-earth (Europium (Eu)) doped Gd2 O3 . To elaborate the scope of the review, we have discussed synthesis, structural and optical properties of lithium (Li) doped Gd2 O3 :Eu. At the end of the review, synthesis, structural and optical properties of Eu doped lutetium oxide (Lu2 O3 ) have been discussed and the results compared with Eu doped Gd2 O3 . The comparison provided the understanding of structural and optical peak position of host and the dopant (Eu).

Green Synthesis of Nanomaterials Using Plant Extract: A Review.

For the last two decades, extensive research is conducted on metal and metal oxide nanoparticles and their application in the field of medical, cosmetics, catalysts, packaging, photonics, agriculture and electronics. However, these nanoparticles show toxicity to the environmental, human and animal health. The toxicity effects of nanoparticles are mainly due to their size, which can easily pass through physiological barriers and also due to the synthesis procedure. The toxicity due to their size cannot be avoided, but toxicity due to the synthesis process can be nullified by adopting the biosynthesis process. Bacteria, fungus, fish scales, plant extracts and algae are used to synthesize metal and metal- oxide nanoparticles such as silver, gold, iron-oxide, zinc-oxide, zirconia, etc. For the last few years, researchers have been working on synthesis methods of plant extracts to produce stable, cost-effective and economical nanoparticles. In this review, we focus on the biosynthesis of nanoparticles using different parts of plant extracts. The review contains a summary of selected papers from 2018-20 with a detailed description of the process of synthesis, mechanism, characterization and their application in various fields of biosynthesized metal and metal oxide nanoparticles.

Quantum fluctuations in percolating superconductors: an evolution with effective dimensionality.

We investigate percolating films of superconducting nanoparticles and observe an evolution from superconducting to metallic to insulating states as the surface coverage of the nanoparticles is decreased. We demonstrate that this evolution is correlated with a reduction in the effective/dominant dimensionality of the system, from 2D to 1D to 0D, and that the physics in each regime is dominated by vortices, phase slips and tunnelling respectively. Finally we construct phase diagrams that map the various observed states as a function of surface coverage (or, equivalently, normal state resistance), temperature and measurement current.