An ab initio density functional theory-based study of the electronic band structure, the elastic, electric, elastoelectric, and linear and nonlinear optical properties of the new ion conductor LiB 6 O 9 F, has been performed. The computed band structure reveals a wide direct band gap. The coefficients of the second order nonlinear susceptibility χ (2) were found to be comparable to those of KH 2 PO 4 . Corresponding experimental investigations of second harmonic generation comply with the respective ab initio calculations.

The complex dielectric constant of pure and cerium doped calcium-barium-niobate (CBN) was studied at frequencies 20 Hz ≤ f ≤ 1 MHz in the temperature range 300 K ≤ T ≤ 650 K and compared with the results for the well known ferroelectric relaxor strontium-barium-niobate (SBN). By the analysis of the systematically taken temperature and frequency dependent measurements of the dielectric constant the phase transition characteristic of the investigated materials was evaluated. From the results it must be assumed that CBN shows a slightly diffuse phase transition without relaxor behavior. Doping with cerium yields a definitely different phase transition characteristic with some indications for a relaxor type ferroelectric material, which are common from SBN

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