Fig. 2
Atomistic interpretation of the electrical conductivity of riebeckite. A sketch of the experimental set-up to measure σ|| (a) and σ⊥ (b); E is the applied dc electric field; in situ temperature-dependent \(\:\stackrel{-}{y}\left(zz\right)y\) polarized Raman spectra of riebeckite measured at 300 K and T’’= 650 K with E||c axis (c) and E⊥c axis (d); temperature evolution of conductivity measured with E||c, σ|| (e) and with E⊥c, σ⊥, (f); white triangles are σ(T) of silica glass as a reference insulator to mark the zero level. The activation energy (in eV) derived from data between T’ and T’’ (shaded in yellow) and above T’’, (shaded in cyan) are also indicated in the plots; the blue dotted lines in (e) and (f) mark the temperature above which σ⊥ stops increasing. Atomic structure plotted with Vesta 3.5.8 (https://jp-minerals.org/vesta/en/)65.
