Influence of growth rate on the epitaxial orientation and crystalline quality of CeO2 thin films grown on Al2O3(0001)

Growth rate-induced epitaxial orientations and crystalline quality of CeO2 thin films grown on Al2O3(0001) by oxygen plasma-assisted molecular beam epitaxy were studied using in situ and ex situ characterization techniques. CeO2 grows as three-dimensional (3D) islands and two-dimensional layers at growth rates of 1-7 angstrom/min and \u3e = 9 angstrom/min, respectively. The formation of epitaxial CeO2(100) and CeO2(111) thin films occurs at growth rates of 1 angstrom/min and \u3e = 9 angstrom/min, respectively. Glancing-incidence x-ray diffraction measurements have shown that the films grown at intermediate growth rates (2-7 angstrom/min) consist of polycrystalline CeO2 along with CeO2(100). The thin film grown at 1 angstrom/min exhibits six in-plane domains, characteristic of well-aligned CeO2(100) crystallites. The content of the poorly aligned CeO2(100) crystallites increases with increasing growth rate from 2 to 7 angstrom/min, and three out of six in-plane domains gradually decrease and eventually disappear, as confirmed by XRD pole figures. At growth rates \u3e = 9 angstrom/min, CeO2(111) film with single in-plane domain was identified. The formation of CeO2(100) 3D islands at growth rates of 1-7 angstrom/min is a kinetically driven process unlike at growth rates \u3e = 9 angstrom/min which result in an energetically and thermodynamically more stable CeO2(111) surface

Multiscale correlative tomography: an investigation of creep cavitation in 316 stainless steel

Creep cavitation in an ex-service nuclear steam header Type 316 stainless steel sample is investigated through a multiscale tomography workflow spanning eight orders of magnitude, combining X-ray computed tomography (CT), plasma focused ion beam (FIB) scanning electron microscope (SEM) imaging and scanning transmission electron microscope (STEM) tomography. Guided by microscale X-ray CT, nanoscale X-ray CT is used to investigate the size and morphology of cavities at a triple point of grain boundaries. In order to understand the factors affecting the extent of cavitation, the orientation and crystallographic misorientation of each boundary is characterised using electron backscatter diffraction (EBSD). Additionally, in order to better understand boundary phase growth, the chemistry of a single boundary and its associated secondary phase precipitates is probed through STEM energy dispersive X-ray (EDX) tomography. The difference in cavitation of the three grain boundaries investigated suggests that the orientation of grain boundaries with respect to the direction of principal stress is important in the promotion of cavity formation

Safety and Efficacy of Sertraline for Depression in Patients With Heart Failure: Results of the SADHART-CHF Trial

The objective was to test the hypothesis that heart failure (HF) patients treated with sertraline will have lower depression scores and fewer cardiovascular events compared to placebo

Safety and Efficacy of Sertraline for Depression in Patients with CHF (SADHART-CHF): A randomized, double-blind, placebo-controlled trial of sertraline for major depression with congestive heart failure

Sertraline, a selective serotonin-reuptake inhibitor (SSRI), has demonstrated substantial mood improvement in patients with post myocardial infarction or with unstable angina. The impact of sertraline on the prognosis and depression of patients with chronic heart failure (HF) and co-morbid major depressive disorder (MDD) is unknown

Upconverting Ho–Yb doped titanate nanotubes

The synthesis of Ho3 +–Yb3 + codoped titanate nanotubes was carried out successfully via a hydrothermal treatment method from a precursor powder. These novel nanotubes treated at RT, 100 °C and 280 °C were studied with the aim of determining their structural and optical properties. As the thermal treatment was increased, their upconversion emission becomes stronger. This behavior was related to reduction of hydroxyl groups and the water on the surface, which resulted in changes in the interlayer distances of the nanotubes