0000000000299723
AUTHOR
Carlos Frontera
Crystal structures of superconducting sodium intercalates of hafnium nitride chloride
Sodium intercalation compounds of HfNCl have been prepared at room temperature in naphtyl sodium solutions in tetrahydrofuran and their crystal structure has been investigated by Rietveld refinement using X-ray powder diffraction data and high-resolution electron microscopy. The structure of two intercalates with space group Rm and lattice parameters a = 3.58131(6) A u , c = 57.752(6) A u , and a = 3.58791(8) A u , c = 29.6785(17) A u is reported, corresponding to the stages 2 and 1, respectively, of NaxHfNCl. For the stage 2 phase an ordered model is presented, showing two crystallographically independent (HfNCl) units with an alternation of the Hf-Hf interlayer distance along the c-axis, …
Elektrónová a pásová štruktúra CuMnAs študovaná optickou a fotoemissinou spektroskopiou
Tetragonal phase of CuMnAs progressively appears as one of the key materials for antiferromagnetic spintronics due to efficient current-induced spin-orbit torques whose existence can be directly inferred from crystal symmetry. Theoretical understanding of spintronic phenomena in this material, however, relies on the detailed knowledge of electronic structure (band structure and corresponding wave functions) which has so far been tested only to a limited extent. We show that AC permittivity (obtained from ellipsometry) and UV photoelectron spectra agree with density functional calculations. Together with the x-ray diffraction and precession electron diffraction tomography, our analysis confi…
A new intermediate intercalate in superconducting sodium-doped hafnium nitride chloride
Anew phase has been observed during the sodiumintercalation of hafnium nitride chloride as intermediate between the host β-HfNCl and the already reported Na 0.29 HfNCl with Tc of 24 K; the new intermediate shows interlayer spacings ranging from 9.48 to 9.67 A°, corresponds to a second stage intercalate of HfNCl and is superconducting with a critical temperature of 20 K. Beltran Porter, Daniel, Daniel.Beltran@uv.es