Department of Materials Science and Engineering, University of Sheffield, Sheffield, S1 3JD, UK.
Published: May 2021
AI Article Synopsis
Article Abstract
A combination of impedance spectroscopy, time-of-flight secondary ion mass spectrometry and literature data are used to show that, (i) the bulk oxide ion conductivity of A-site, alkaline earth-doped BiFeO3 (BF) is independent of the ionic radius of the alkaline earth ion (Ca, Sr, Ba) and, (ii) despite very different A-site environments in (Na1/2Bi1/2)TiO3 and BF, similar high levels and optimisation of bulk oxide ion conductivity in these Bi-based tilted perovskites is achieved at modest acceptor doping levels of ∼1-10%. These results clearly demonstrate that optimisation of oxide ion conductivity in these materials requires concepts beyond a simple crystallochemical approach based on matching the ionic radii of acceptor dopant and host lattice ions.
High-level quantum chemical calculations are performed for the (NH)MO and (NH)MO species (M = Ti-Cu), extending our previous work on the bare MO ions. The potential energy curves along the M-O distance are constructed for the ground and multiple excited electronic states of (NH)MO and are compared to those of MO. We see that ammonia stabilizes the oxo states (MO) over the oxyl (MO) ones.
Oxygen vacancies in Ruddlesden-Popper (RP) perovskites (PV) [AO][ABO] play a pivotal role in engineering functional properties and thus understanding the relationship between oxygen-vacancy distribution and physical properties can open up new strategies for fine manipulation of structure-driven functionalities. However, the structural origin of preferential distribution for oxygen vacancies in RP structures is not well understood, notably in the single-layer ( = 1) RP-structure. Herein, the = 1 RP phase SrNdZnO was rationally designed and structurally characterized by combining three-dimensional (3D) electron diffraction and neutron powder diffraction.
17-Estradiol (E2) is a natural steroidal estrogen essential for a variety of physiological functions in organisms. However, external E2, which is renowned for its potent biological effects, is also considered to be an endocrine-disrupting compound (EDC) capable of disturbing the normal operation of the endocrine system, even at nanogram-per-liter (ng/L) concentrations. Studies have revealed that medical and livestock wastewater can be contaminated with E2, which poses potential risks to human health.
Chlorinated coumarins, which are as cytotoxic as highly toxic halobenzoquinones toward CHO-K1 cells, have recently been identified as disinfection byproducts in drinking water disinfection processes. Therefore, detecting coumarins in water samples collected at various stages from drinking water treatment plants helps assess the formation of chlorinated coumarins in drinking water. Hence, a simple, rapid, accurate, and sensitive method for quantifying coumarins in water samples is required.
Lipids are indispensable components of living organisms and play pivotal roles in cell-membrane fluidity, energy provision, and neurotransmitter transmission and transport. Lipids can act as potential biomarkers of diseases given their abilities to indicate cell-growth status. For example, the lipid-metabolism processes of cancer cells are distinct from those of normal cells owing to their rapid proliferation and adaptation to ever-changing biological environments.
