Abstract: | The transmittance and absorption spectra of a high‐quality Zn2TiO4 single crystal have been measured along the a‐axes at room‐temperature in the range of 200‐1000 nm. The wavelength dependent refractive index, extinction coefficient, real and imaginary parts of the complex dielectric constant of the Zn2TiO4 crystal have been derived from the measured T and α spectra. By fitting the refractive index spectrum, the Sellmeier dispersion equation of the Zn2TiO4 crystal has been obtained. The validity of Cauchy‐Sellmeier equation has been evaluated in the energy range of 2.90–3.20 eV representing the Urbach tail. Applying the single‐effective oscillator model, the dispersion energy Ed and the oscillator energy E0 have been determined as 18.76 and 5.05 eV, respectively. The obtained dispersion energy Ed takes on ionic crystal value. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) |