Figure 1

Reversible temperature variation of the positron lifetime ${\tau }_1$ in the decagonal ${\mathrm{Al}}_{71.5}{\mathrm{Ni}}_{14}{\mathrm{Co}}_{14.5}$ quasicrystal with data from various measuring runs. Positron lifetimes measured at ambient temperature after quenching from 1180 or 1000 K are given additionally together with isochronal annealing data (full diamonds). The dotted line is drawn for guiding the eye.Reuse & Permissions

Figure 2

Reversible temperature variation of the $W$ parameter in the decagonal ${\mathrm{Al}}_{71.5}{\mathrm{Ni}}_{14}{\mathrm{Co}}_{14.5}$ quasicrystal with data from various measuring runs. $W$ parameters measured at ambient temperature after quenching from 1180 and 1000 K are given additionally together with isochronal annealing data (full diamonds). The bold line indicates a fit of the volume averaged positron annihilation in the ordered domains and in the disordered structure (see text) taking the temperature dependent domain size from neutron scattering [3] into account. The dotted line is drawn for guiding the eye.Reuse & Permissions

Figure 3

(a) Coincident Doppler broadening spectra in the momentum range of $0–40\times {10}^{-3}{m}_{0}c$ of the decagonal ${\mathrm{Al}}_{71.5}{\mathrm{Ni}}_{14}{\mathrm{Co}}_{14.5}$ quasicrystal measured at various temperatures, together with the spectra for pure Al, Ni, and Co. Each spectrum is normalized to the total number of counts. (b) Ratio curves of the coincident Doppler broadening spectra of the decagonal ${\mathrm{Al}}_{71.5}{\mathrm{Ni}}_{14}{\mathrm{Co}}_{14.5}$ quasicrystal measured at various temperatures together with those for pure Al, pure Ni, and pure Co. All spectra are normalized to that of pure Al.Reuse & Permissions