Andreas Leithe-Jasper
In solid-state compounds, the valence of europium can sometimes be mixed -- which is especially favored in structures with several positions for the europium atoms. In this work, we study the Eu-based intermetallic noncentrosymmetric system…
A procedure for quantifying the U $5f$ electrons' covalence and degree of localization in U intermetallic compounds is presented. To this end, bulk sensitive hard and soft x-ray photoelectron spectroscopy were utilized in combination with…
Vibrational and elastic properties of the $R$Fe$_{4}$Sb$_{12}$ skutterudites are investigated by, respectively, temperature $(T)$ dependent extended X-ray absorption fine structure (EXAFS) and pressure $(P)$ dependent x-ray diffraction…
Using inelastic x-ray scattering beyond the dipole limit and hard x-ray photoelectron spectroscopy we establish the dual nature of the U $5f$ electrons in UM$_2$Si$_2$ (M = Pd, Ni, Ru, Fe), regardless of their degree of delocalization. We…
The puzzling situation where some thermodynamic quantities require a single-gap description, while others need a more complex gap scenario, is discussed. Our approach reveals that in some cases, the conclusions based on measurements of only…
Precise measurements of the thermodynamic critical field ($B_{\rm c}$) in type-I noncentrosymmetric superconductor BeAu were performed by means of the muon-spin rotation/relaxation technique. The temperature evolution of $B_{\rm c}$ can not…
Single crystals of Sc5Rh6Sn18 were grown from Sn-flux. The crystal structure (SG: I41/acd, a = 13.5529(2) {\AA}, c = 27.0976(7) {\AA}) was studied by high-resolution X-ray diffraction on powder and single crystal material as well as by TEM.…
The magnetic, thermal and transport properties as well as electronic band structure of MnPtSi are reported. MnPtSi is a metal that undergoes a ferromagnetic transition at $T_{\mathrm{C}}=340$(1) K and a spin-reorientation transition at…
We present muon spin rotation and relaxation (muSR) measurements as well as demagnetising field corrected magnetisation measurements on polycrystalline samples of the noncentrosymmetric superconductor BeAu. From muSR measurements in a…
We report on the electronic band structure, structural, magnetic and thermal properties of Ce$_2$Rh$_3$Sn$_5$. Ce $L_{\mathrm{III}}$-edge XAS spectra give direct evidence for an intermediate valence behaviour. Thermodynamic measurements…
We investigated the superconducting order parameter of the filled skutterudite LaPt4Ge12, with a transition temperature of Tc = 8.3 K. To this end, we performed temperature and magnetic-field dependent specific-heat and thermal-conductivity…
Two new ternary borides $TM$$_7$Fe$_3$B$_8$ ($TM$ = Nb, Ta) were synthesized by high-temperature thermal treatment of samples obtained by arc-melting. This new type of structure with space group $P$6/$mmm$, comprises $TM$ slabs containing…
In a joint experimental and theoretical study, we investigate the isostructural collapse from the ambient pressure tetragonal phase to a collapsed tetragonal phase for non-superconducting metallic SrFe2As2 and SrFe_1.8Ru_0.2As_2. The…
The electronic structure and physical properties of the pnictide compound families $RE$OFeAs ($RE$ = La, Ce, Pr, Nd, Sm), $A$Fe$_{2}$As$_{2}$ ($A$ = Ca, Sr, Ba, Eu), LiFeAs and FeSe are quite similar. Here, we focus on the members of the…