arXiv subjects

A. Trapananti

Publications and source records attributed to A. Trapananti.

3 recordsLinked to original sources

arXiv2020

Potassium-Doped Para-Terphenyl: Structure, Electrical Transport Properties and Possible Signatures of a Superconducting Transition

Preliminary evidence for the occurrence of high-Tc superconductivity in alkali-doped organic materials, such as potassium-doped p-terphenyl (KPT), were recently obtained by magnetic susceptibility measurements and by the opening of a large superconducting gap as measured by ARPES and STM techniques. In this work, KPT samples have been synthesized by a chemical method and characterized by low-temperature Raman scattering and resistivity measurements. Here, we report the occurrence of a resistivity drop of more than 4 orders of magnitude at low temperatures in KPT samples in the form of compressed powder. This fact was interpreted as a possible sign of a broad superconducting transition taking place below 90 K in granular KPT. The granular nature of the KPT system appears to be also related to the 20 K broadening of the resistivity drop around the critical temperature.

cond-mat.supr-con↗

arXiv2017

Project of refurbishment of the GILDA beamline at the ESRF

This document presents the refurbishment project for GILDA, the Italian CRG beamline at the ESRF. After a short introduction to the beamline and its achievements in the last years, the base ideas and concepts driving the design are exposed whereas a more detailed technical description of the new instrument is given in a further section. An analysis of the costs and a schedule for the implementation of the program is also presented in the last part of the document.

physics.ins-det↗

arXiv2012

Tuning the Eu valence in EuPd_3B_x: pressure versus valence electron count - a combined computational and experimental study

In a joint theoretical and experimental study we investigate the pressure dependence of the Eu valence in EuPd_3B_x (0 <= x <= 1). Density functional band structure calculations are combined with x-ray absorption and x-ray diffraction measurements under hydrostatic pressures up to 30 GPa. It is observed that the heterogenous mixed-valence state of Eu in EuPd_3B_x (x >= 0.2) can be suppressed partially in this pressure range. From the complementary measurements we conclude that the valence change in EuPd_3B_x is mainly driven by the number of additional valence electrons due to the insertion of boron, whereas the volume change is a secondary effect. A similar valence change of Eu in Eu_{1-x}La_xPd_3 is predicted for x >= 0.4, in line with the suggested electron count scenario.

cond-mat.str-el↗