Bulk photovoltaic effect in BaTiO3

In melt-grown BaTiO₃ single crystals steady-state photocurrents proportional to the light intensity have been observed parallel to the crystallographic c-axis. The open-circuit photovoltage exceeds the value of the band gap. Light polarized parallel and perpendicular to the c-axis respectively produces photovoltages with opposite sign. This photovoltaic effect is restricted to the ferroelectric phase.     

Thermische Untersuchungen der Kristallisation von Korund

With thermal analysis (DTA/TG) the crystallisation behaviour of corundum with influence of the fluor compounds were investigated. The formation of aluminium fluoridhydroxide in the temperature range 400-600°C are observed. Through the influence of AIF₃ or HF the strong exothermic effect increased and a rapid loss of mass were noticed. The particle of corundum grow more, when the exothermic effects are large. We supposed, that also these exothermic effect will be due to the decomposition of may be adsorbed AIOF gas molecules. This revised version was published online in July 2006 with corrections to the Cover Date.