Drastic enhancement of electronic correlations induced by hydrogen insertion in the cerium intermetallic compound CeFeSi.

We report a comparative study of two cerium-based intermetallic compounds: CeFeSi with an anti-PbFCl type structure, and CeFeSiH with a ZrCuSiAs type structure. The latter is obtained from CeFeSi through hydrogen insertion. Our results are based on x-rays, transport, thermodynamic and magnetic measurements.

Topotactic fluorination of intermetallics as an efficient route towards quantum materials.

Intermetallics represent an important family of compounds, in which insertion of light elements (H, B, C, N) has been widely explored for decades to synthesize novel phases and promote functional materials such as permanent magnets or magnetocalorics. Fluorine insertion, however, has remained elusive so far since the strong reactivity of this atypical element, the most electronegative one, tends to produce the chemical decomposition of these systems. Here, we introduce a topochemical method to intercalate fluorine atoms into intermetallics, using perfluorocarbon reactant with covalent C-F bonds.

Performance evaluation of the mouse version of the LabPET II PET scanner.

The LabPET II is a new positron emission tomography technology platform designed to achieve submillimetric spatial resolution imaging using fully pixelated avalanche photodiodes-based detectors and highly integrated parallel front-end processing electronics. The detector was designed as a generic building block to develop devices for preclinical imaging of small to mid-sized animals and for clinical imaging of the human brain. The aim of this work is to assess the physical characteristics and imaging performance of the mouse version of LabPET II scanner following the NEMA NU4-2008 standard and using high resolution phantoms and in vivo imaging applications.

Dual-Threshold Time-over-Threshold Nonlinearity Correction for PET Detectors.

The Time-over-Threshold (ToT) analog-to-digital signal processing approach provides a power-efficient and cost-effective technique to extract all relevant information from detectors in high-energy physics and Positron Emission Tomography (PET) imaging. In this work, three calibration methods were investigated to correct the inherent nonlinear response of the ToT data using 1) -ray sources of various energies, 2) internal electronic gain variation in the LabPET II ASIC in combination with a single energy -ray source, and 3) internal gain variation along with an embedded pulse charge generator in replacement of a -ray source. The electronic gain calibration technique was shown to achieve equivalent correction accuracy as the -ray sources calibration.

Effect of Carbon Insertion on the Structural and Magnetic Properties of NdScSi.

The investigation of layered intermetallic compounds containing light elements like hydrogen has great potential for superconductivity. We studied the insertion of carbon atoms in CeScSi-type intermetallics (an ordered variant of the LaSb structure type), and here, we report the new carbide NdScSiC. Carbon insertion keeps the pristine compound's space group, 4/, but causes an anisotropic expansion of the unit cell with an increase in the parameter and a decrease of the parameter.