Diffuse neutron scattering from the superionic phase of Cu2Se

Derivation of Inter-Atomic Force Constants of Cu₂O from Diffuse Neutron Scattering Measurement

“…One is from the thermal vibrations of atoms and the other contribution comes from the static displacements of atoms from the regular atomic positions. These two contributions could be separated by scattering measurements using triple-axis spectrometer in diffractometer two-crystal configuration and in three -axis elastic scattering mode with analyzer crystal [17].…”

Structural behaviour of β-Cu2−δSe (δ=0, 0.15, 0.25) in dependence on temperature studied by synchrotron powder diffraction

“…According to molecular dynamics simulations [14], the minimum energy diffusion pathway in the anti-fluorite structure passes alternately tetrahedral and octahedral voids through the octahedral 4(b) site at (1/2, 1/2, 1/2). Most structure determinations, however, did not reveal any occupation of copper ions in the centre of the octahedron [6][7][8][9]12,13]. Some publications, however, report intensity changes of reflections as a function of temperature and unusual thermal expansion in ␤-Cu 2−δ Se (δ = 0-0.25) [4,15,16].…”

“…Previous investigations revealed a face centred cubic (fcc) lattice for the selenium atoms with the copper ions distributed on the different interstitial sites within the tetrahedral and octahedral voids [3][4][5][6][7][8][9][10][11][12][13]. Tetrahedral and octahedral voids in the fcc lattice share faces, whereas similar "octahedron-octahedron" and "tetrahedron-tetrahedron" voids are connected by common edges.…”

An investigation of the structural dynamics in the fast ionic conductor Cu2−δSe using neutron scattering

“…At the same time disorder gives rise to broad diffuse maxima observed in neutron diffraction patterns of polycrystalline and single crystal samples of copper selenide [7,10,11]. The diffuse background generally contains both elastic and inelastic scattering components which originate from the static disorder and dynamic correlations.…”