Preparation and electrical properties of inorganic electride [Y(2)Ti(2)O(6)](2+)(2e(−))

Oxygen-depleted samples [Y(2)Ti(2)O(7−x)](2x+)(2xe(−)) (0 ≤ x ≤ 1.0) were prepared by reducing Y(2)TiO(7) powders at 500 °C to 650 °C using CaH(2) as a reductive agent, where x represents the content of [Image: see text] , which was determined by thermogravimetric analysis. Powder X-ray diffraction patterns illustrate that the pure pyrochlore phase is kept for the samples with x ≤ 1.0, whereas the apparent x values surpass 1.0, and the impurity phase Y(2)O(3) appears. The electride [Y(2)Ti(2)O(7−x)](2x+)(2xe(−)) (x ≈ 1.0) can be obtained under a reductive condition, in which the concentration of V(O) is 7.75 × 10(21) cm(−3). The electron paramagnetic resonance measurements gave the concentration of unpaired electrons in the electride as 1.30 × 10(21) cm(−3), indicating that the degree of the ionization of [Image: see text] is less than 10%. Conductivity measurements for a sintered pellet sample (relative density ∼ 70%) indicate that the electride has quite high conductivity (∼1.09 S cm(−1) at 300 K). The conduction was interpreted by using the variable range hopping mechanisms.