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A radiation-resistant nuclear battery combining betavoltaic and photovoltaic techniques was demonstrated using Ce-doped Gd3Ga3Al2O12 single-crystal scintillator. The present device comprising 1 mm thick Ce-doped GGAG single-crystal scintillator and Si-based p–i–n diode produced an electric power output of 48 nW with a short-circuit current of 490 nA and an open-circuit voltage of 0.18 V using a 3 mCi 106Ru source. Long-term radiation stability test carried out for more than 4000 h revealed that there was no significant reduction in the output of beta-photovoltaic device (with scintillator), whereas there was 68% reduction in the output power for the betavoltaic device (without scintillator). The electron beam irradiation of 1 mm thick Ce-doped GGAG scintillator up to a dose level of 5 MGy using 10 MeV electron beam indicated a power degradation by 4% suggesting a reasonably long battery life (∼15 years) with 90Sr-90Y source. [ABSTRACT FROM AUTHOR]

Room temperature transformation from anatase (A-TiO2) to rutile (R-TiO2) thin films through an intermediate mixed phase on stainless steel driven by a controlled oxygen flow rate (OFR) is investigated. Such OFR dependent phase transition is confirmed by X-ray diffraction and also consistent with X-ray absorption spectroscopy at Ti L and O K-edges, showing a long range ordering in TiO6 octahedral symmetry. X-ray photoelectron spectroscopy reveals a gradual reduction in Ti2O3 and/or TiO intermediate phases with increasing OFR. Finally, an enhanced photocatalytic activity is observed in the mixed phase and discussed in terms of photo-generated charge transport in the type-II staggered band structure between A-TiO2 and R-TiO2 phases. [ABSTRACT FROM AUTHOR]