Epitaxially stabilized growth of orthorhombic LuScO3 thin films

Metastable lutetium scandate (LuScO3) thin films with an orthorhombic perovskite structure have been prepared by molecular-beam epitaxy and pulsed-laser deposition on NdGaO3(110) and DyScO3(110) substrates. Stoichiometry and crystallinity were investigated using Rutherford backscattering spectrometry/channeling, x-ray diffraction, and transmission electron microscopy. The results indicate that LuScO3, which normally only exists as a solid solution of Sc2O3 and Lu2O3 with the cubic bixbyite structure, can be grown in the orthorhombically distorted perovskite structure. Rocking curves as narrow as 0.05 degrees were achieved. A critical film thickness of approximately 200 nm for the epitaxially stabilized perovskite polymorph of LuScO3 on NdGaO3(110) substrates was determined. (C) 2007 American Institute of Physics

Characterization of epitaxial lanthanum lutetium oxide thin films prepared by pulsed-laser deposition as an alternative gate dielectric

Launch of the National Stroke Foundation stroke awareness campaigns has occurred annually during Stroke Week (September) since 2004. From 2006, the campaign used FAST (Face, Arm, Speech, Time) with calling an ambulance added in 2007. The aim of this study was to explore the impact of these campaigns on ambulance dispatches for stroke (Medical Priority Dispatch Card 28) in Melbourne, Australia.A cross-sectional study examining the monthly proportions of ambulance dispatches for stroke between August 1999 and 2010 was conducted. The proportions of dispatches for stroke were used due to increases in the population and in ambulance dispatches over the study period. These proportions were statistically compared for the month before Stroke Week (August) and the month after Stroke Week (October) for each year and seasonal variation was examined.Between 1999 and 2009, the annual proportion of dispatches for stroke increased from 2.1% (n=4327) to 2.95% (n=9918). When stroke dispatches in August were compared with those in October, a significant increase in October was only detected since the call an ambulance message was added to FAST: 2007 (2.62% to 3.00%, P=0.006), 2008 (2.62% to 3.05%, P=0.003), and 2009 (2.70% to 3.09%, P=0.007). From 2005, the peak season for stroke dispatches shifted from winter to spring.Ambulance dispatches for stroke significantly increased after the National Stroke Foundation campaigns began, particularly in years receiving greater funding and featuring the FAST symptoms and the message to call an ambulance. Monitoring ambulance use appears to be an effective measure of campaign penetration

Electronic structure of silicon interfaces with amorphous and epitaxial insulating oxides: Sc2O3, Lu2O3, LaLuO3

Spectroscopy of internal photoemission, photoconductivity, and optical absorption is used to characterize the differences in the electronic structure of interfaces of silicon with several oxides (Sc2O3, Lu2O3, LaLuO3) grown as epitaxial layers or as amorphous films. As compared to their crystalline counterparts, the amorphous oxides exhibit significant band-tail states predominantly associated with the smearing-out of the conduction band edge. In SC203 a difference in bandgap width between the crystalline and amorphous phases, caused by variation of the energy of the oxide valence band top, is also observed. No structure-sensitive interface dipoles are found to affect the band alignment at the Si/oxide interfaces

Optical band gap and magnetic properties of unstrained EuTiO3 films

Phase-pure, stoichiometric, unstrained, epitaxial (001)-oriented EuTiO3 thin films have been grown on (001) SrTiO3 substrates by reactive molecular-beam epitaxy. Magnetization measurements show antiferromagnetic behavior with T-N=5.5 K, similar to bulk EuTiO3. Spectroscopic ellipsometry measurements reveal that EuTiO3 films have a direct optical band gap of 0.93 +/- 0.07 eV