Electrical conductivity of Al- and Ti-bearing davemaoite

Determine how Al and Ti substitutions affect the electrical conductivity of davemaoite under lower-mantle pressure–temperature conditions, including how substitution-induced changes in oxygen-vacancy concentration and the tetragonal-to-cubic transition influence ionic transport.

Background

The study measures the electrical conductivity of compositionally pure, nominally dry CaSiO3 davemaoite and treats it as an end-member constraint. Natural davemaoite in subducted oceanic crust can contain appreciable Al and Ti, with Al substitution potentially generating additional oxygen vacancies and Ti substitution modifying the structural transition.

Because the conductivity enhancement observed across the tetragonal-to-cubic transition may be affected by Al- and Ti-induced shifts in the transition boundary, the conductivity of compositionally realistic davemaoite remains unresolved experimentally. Establishing these effects is necessary for assessing the contribution of subducted oceanic crust to lower-mantle conductivity anomalies.