On the dielectric constant of titanium dioxide

Abstract Conductive rutile TiO2 has received considerable attention recently due to a number of applications. However, the static dielectric constant in conductive, reduced or doped TiO2 appears to cause controversy with reported values in the range 100-10000. In this work, we propose a method for measurements of the dielectric constant in conductive, n-type TiO2 that involves: (i) hydrogen implantation to form a donor profile at a known depth, and (ii) capacitance-voltage measurements for donor profiling. We can not confirm the claims stating an extremely high dielectric constant. On the contrary, the dielectric constant of conductive, reduced rutile TiO2 is similar to that of insulating rutile TiO2 established previously, with a Curie-Weiss type temperature dependence and the values in the range 160-240 along the c-axis.