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We have studied the anisotropic magnetic properties of Ln2Re3Si5 (Ln=Ce, Pr, Ho) single crystals by means of isothermal magnetization (M), magnetic susceptibility (χ), and heat capacity (CP). The Ce2Re3Si5 did not show any magnetic transition down to 2 K, and exhibits a low value of magnetic susceptibility. This suggests that Ce ions are in the intermediate valence state. Pr2Re3Si5 was found to exhibit antiferromagnetic (AFM) ordering at TN= 9 K in, a spin flip-like metamagnetic transition was observed at 3.5 T for H || [001] in the M vs. H plot. The anisotropic magnetic properties of Pr2Re3Si5 have been explained by the crystalline electric field (CEF) effect based on a point charge model. From the CEF analysis, we find that the 9-fold degenerate (2J+1) ground state splits into 9 levels with an overall splitting of 1179 K. The Ho2Re3Si5, on the other hand, shows two AFM transitions at TN1= 3.8 K and TN2= 4.2 K. Interestingly, three field-induced metamagnetic transitions near 0.45 T, 1 T, and 1.5 T at 1.8 K in Ho2Re3Si5 have been observed. These compounds exhibit significant anisotropy in magnetic properties along two main crystallographic directions viz., [100] and [001]. [ABSTRACT FROM AUTHOR]

Solid-state scintillation materials reach a pick of their popularity and one of such attractive materials is the new Gd3Al2Ga3O12:Ce single crystal with unique and promising scintillation properties. The fundamental optical properties of this crystal and the effect of the composition deviations on them are studied poorly. This investigation is focused on the estimation of the influence of the Al to Ga partial substitution in the Gd3Al5-xGaxO12 cationic sublattice on the transmission spectra and refractive indices. In this work transmission spectral dependences and the refractive indices dispersion dependences were obtained by spectrophotometric methods using certified methods on calibrated equipment. The effect of the cationic substation on the transmission spectra is weak, slight decrease in intensity of Al:Ga ration 3:2 samples was observed in the wavelength region 200-350 nm. In the studied wavelength range 200-700 nm refractive index values of the crystals with an Al to Ga ratio 3:2 are lower than values of the crystals with a 2:3 ratio. [ABSTRACT FROM AUTHOR]

A novel, "single-shot" fluorescence imaging technique has been demonstrated on the B16 beamline at the Diamond Light Source synchrotron using the HEXITEC energy dispersive imaging detector. A custom made furnace with 200µm thick metal alloy samples was positioned in a white X-ray beam with a hole made in the furnace walls to allow the transmitted beam to be imaged with a conventional X-ray imaging camera consisting of a 500 µm thick single crystal LYSO scintillator, mirror and lens coupled to an AVT Manta G125B CCD sensor. The samples were positioned 45° to the incident beam to enable simultaneous transmission and fluorescence imaging. The HEXITEC detector was positioned at 90° to the sample with a 50µm pinhole 13cm from the sample and the detector positioned 2.3m from pinhole. The geometric magnification provided a field of view of 1.1x1.1mm² with one of the 80x80 pixels imaging an area equivalent to 13µm². Al-Cu alloys doped with Zr, Ag and Mo were imaged in transmission and fluorescence mode. The fluorescence images showed that the dopant metals could be simultaneously imaged with sufficient counts on all 80x80 pixels within 60s, with the X-ray flux limiting the fluorescence imaging rate. This technique demonstrated that it is possible to simultaneously image and identify multiple elements on a spatial resolution scale ~10µm or higher without the time consuming need to scan monochromatic energies or raster scan a focused beam of X-rays. Moving to high flux beamlines and using an array of detectors could improve the imaging speed of the technique with element specific imaging estimated to be on a 1s timescale. [ABSTRACT FROM AUTHOR]