On the permittivity of titanium dioxide

Abstract

Abstract Conductive rutile TiO 2 has received considerable attention recently due to multiple applications. However, the permittivity in conductive, reduced or doped TiO 2 appears to cause controversy with reported values in the range 100–10,000. In this work, we propose a method for measurements of the permittivity in conductive, n-type TiO 2 that involves: (i) hydrogen ion-implantation to form a donor concentration peak at a known depth, and (ii) capacitance–voltage measurements for donor profiling. We cannot confirm the claims stating an extremely high permittivity of single crystalline TiO 2 . On the contrary, the permittivity of conductive, reduced single crystalline TiO 2 is similar to that of insulating TiO 2 established previously, with a Curie–Weiss type temperature dependence and the values in the range 160–240 along with the c-axis.