Interplay between spherical periodicity and angular correlation

We report on structural properties and the resistivity of amorphous (In ₅₀Sb ₅₀) _100−xAu _x (0 < x < 80). Immediately after deposition at T = 4 K the static structure was measured by electron diffraction and the resistivity by a four-probe technique. The structural data can be described as induced by a resonance effect (Hume–Rothery-, Peierls-like) between the electronic system and the forming static structure. If the electronic system is changed, the structure adjusts to the new situation. With increasing Au-content (shrinking the Fermi-sphere diameter), for example, a resonance-induced structural peak at 2 k _F shifts to lower scattering values. By analyzing the static structure in even more detail, indications of angular correlations appear, quite similar as has been observed in amorphous precursor alloys of quasicrystals. After deposition the resistivity is quite large at the In ₅₀Sb ₅₀ – rich side. Annealing alloys with x > 0 gives a sharp decrease by roughly 10% around T = 160 K which is interpreted as a separation into two amorphous phases. One which is In ₅₀Sb ₅₀ – rich or may even consist of pure In ₅₀Sb ₅₀, and another one which is enriched by Au. Around T = 300 K there is a second resistivity drop, interpreted as the crystallization of a spherically-periodic ordered Au-rich metallic phase which itself can be described as a so-called amorphous Hume–Rothery phase, stabilized by the electronic system.