A hyperfine look at titanium dioxide

Titanium dioxide is a commonly used material in a wide range of applications, due to its low price, and the increasing demand for it in the food- and pharmaceutical industries, and for low- and high-tech applications. Time-differential perturbed angular correlation (TDPAC) and Mössbauer spectroscopy measurements have a local character and can provide important and new information on the hyperfine interactions in titanium dioxide. With the application of characterization techniques and radioactive beams, these methods have become very powerful, especially for the determination of temperature dependence of hyperfine parameters, even at elevated temperatures. Such measurements lead to a better understanding of lattice defects and irregularities, including local environments with low fractions of particular defect configurations that affect electric quadrupole interactions. At ISOLDE-CERN, physicists benefit from the many beams available for the investigation of new doping configurations in titanium dioxide. We report the annealing study of titanium dioxide by means of the time differential perturbed γ-γ angular correlation of 111mCd/111Cd in order to study the possible effects of vacancies in hyperfine parameters. This paper also provides an overview of TDPAC measurements and gives future perspectives.