We report the microstructure and gas-sensing properties of a nonequilibrium TiO(2)-SnO(2) solid solution prepared by sol-gel method. In particular, we focus on effect Cd doping sensing behavior sensor. Of all volatile organic compound gases examined, sensor with exhibits exclusive selectivity as well high sensitivity to formaldehyde, main harmful indoor gas. The key quantities, maximum sensitivity, optimal working temperature, response recovery time, are found meet basic industrial needs....

Defects play significant roles in properties of graphene and related device performances. Most studies defects focus on their influences electronic or luminescent optical properties, while controlling infrared optoelectronic performance by defect engineering remains a challenge. In the meantime, pristine has very low photoresponses ~0.01 A/W due to fast photocarrier dynamics. Here we report regulating reduced oxide phototransistors atomic structure control for first time. The transport...

Abstract Grain boundary (GB) phase transformations often occur in polycrystalline materials while exposed to external stimuli and are universally implicated substantially affecting their properties, yet atomic-scale knowledge on the transformation process is far from developed. In particular, whether GBs loaded with defects due treatments can still be conventionally considered as disordered areas kinetically trapped structure or turn ordered debated. Here we combine advanced electron...

Atomic-scale analysis of the cation valence state distribution will help to understand intrinsic features oxygen vacancies (VO ) inside metal oxide nanocrystals, which, however, remains a great challenge. In this work, cerium states across ultrafine CeO2 nanocubes (NCs) perpendicular {100} exposed facet is investigated layer-by-layer using state-of-the-art scanning transmission electron microscopy-electron energy loss spectroscopy. The effect size on Ce NCs demonstrated as changed from 11.8...

Magnetic tunnel junctions (MTJs) constitute a promising building block for future nonvolatile memories and logic circuits. Despite their pivotal role, spatially resolving chemically identifying each individual stacking layer remains challenging due to localized features that complicate characterizations limiting understanding of the physics MTJs. Here, we combine advanced electron microscopy, spectroscopy, first-principles calculations obtain direct structural chemical imaging atomically...

In the fundamental understanding of magnetic interactions between atoms in solids, crystal lattice is one key parameters.As effective tool for controlling using tensile stress limited, there are only few demonstrations control properties with expanding structure.Here, we observe that Curie temperature (Tc) quasi two-dimensional Cr2Ge2Te6 NiO overlayer doubles from ~60 K to ~120 K, describe a clear correlation expansion, which characterized by several probes and computational approaches,...

Quantum spin liquids, which are versions of quantum matter, have been sought after in systems with geometrical frustration. We show that disorder drives a classical magnet into liquid through conducting NMR experiments on an organic Mott insulator, $\ensuremath{\kappa}\text{\ensuremath{-}}({\mathrm{ET})}_{2}\mathrm{Cu}[\mathrm{N}({\mathrm{CN})}_{2}]\mathrm{Cl}$. Antiferromagnetic ordering the pristine crystal, when irradiated by x rays, disappears. Spin freezing, gap, and critical slowing...

The possibility of a magnetic field controlling the chirality matter has been debated for long time. Here, we report successful induction in noncentrosymmetric canted antiferromagnet, CuB2O4, by application low intensity static field. is reversed 90 degrees rotation direction gives rise to gigantic enhancement magnetochiral dichroism this material. ability switch handedness combination with large optical effect allows us design new devices such as magnetically controllable isolator.

The structural, adsorptive, and electronic properties of oxygen adsorption on anatase TiO2 are investigated by first-principles calculations with special focus two experimentally confirmed surfaces. We find that compared (101) surface, the (001) surface exhibits lower energy, reduced band gap, larger charge transfer, thereby holding potential for improvement sensitivity to reductive gases. Moreover, is found be more active in adsorption. These findings render a careful synthesis crystals so...

Coaxing correlated materials to the proximity of insulator-metal transition region, where electronic wavefunctions transform from localized itinerant, is currently subject intensive research because hopes it raises for technological applications and also its fundamental scientific significance. In general, this tuning achieved by either chemical doping introduce charge carriers, or external stimuli lower ratio Coulomb repulsion bandwidth. study, we combine experiment theory show that...

Although the function and stability of catalysts are known to significantly depend on their dispersion state support interactions, mechanism catalyst loading has not yet been elucidated. To address this gap in knowledge, study elucidates Pt based a detailed investigation interaction between species localized polarons (Ce3+) associated with oxygen vacancies CeO2(100) facets. Furthermore, an effective method was proposed for achieving high catalytic activity while maintaining stability....

We demonstrate that origin of the long-standing contact issue in silicon carbide devices can be understood and technologically manipulated at atomic level. Using advanced transmission electron microscopy, we attribute qualitatively formation ohmic contacts to an epitaxial, coherent, atomically ordered interface. Quantitatively, first-principles calculations predict this interface trap layer carbon hence enable lowered Schottky barrier enhanced quantum transport. The combined experimental...

The structural, electronic, and adhesive properties of the $4\text{H-SiC}(0001)/{\text{Ti}}_{3}{\text{SiC}}_{2}(0001)$ interface are systematically investigated by first-principles calculations. A total 96 candidate geometries considered, encompassing four SiC terminations, each which involves six ${\text{Ti}}_{3}{\text{SiC}}_{2}$ terminations stacking sequences. We find that fundamental influence substrate on optimal Si-terminated is twofold characterized atomically pulling interfacial C...

Transition-metal impurities gettered by grain boundaries (GBs) act as recombination centers of carriers and are regarded to be harmful defects in multicrystalline silicon (mc-Si) used for solar cell production. In this study, gettering iron Σ3 GBs mc-Si was investigated using transmission electron microscopy annular dark-field (ADF) imaging. the clean specimen, both straight Σ3{111} GB zig-zag Σ3{110}, {112} not electrically active, whereas become active when contaminated with iron. ADF...

Combining advanced transmission electron microscopy with high-precision first-principles calculation, atomic-scale structures of the LaAlO3/TiO2 interface are investigated and bridged to their electronic property at atomic level. Experimentally, deposited TiO2 thin film is demonstrated have an anatase phase bond directly LaAlO3 substrate in epitaxial, coherent, atomically abrupt fashion. The atomic-resolution microscopic images reveal that can be terminated either AlO2 or LaO layer, which...

We report on the atomic ordering of B-site transition metals and magnetic properties epitaxial La${}_{2}$CrFeO${}_{6}$ double-perovskite films grown by pulsed-laser deposition under various conditions. The highest-ordered sample exhibited a fraction antisite disorder only 0.05 saturation magnetization \ensuremath{\sim}2 ${\ensuremath{\mu}}_{B}$ per formula unit at 5 K. result is consistent with antiferromagnetic local spin moment...

Abstract Polycrystalline metal oxides find diverse applications in areas such as nanoelectronics, photovoltaics and catalysis. Although grain boundary defects are ubiquitous their structure electronic properties very poorly understood since it is extremely challenging to probe the of buried interfaces directly. In this paper we combine novel plan-view high-resolution transmission electron microscopy first principles calculations provide atomic level understanding boundaries barrier layer a...

We demonstrate local crystal structure analysis based on annular dark-field (ADF) imaging in scanning transmission electron microscopy (STEM). Using a stabilized STEM instrument and customized software, we first realize high accuracy of elemental discrimination atom-position determination with 10-pm-order accuracy, which can reveal major cation displacements associated variety material properties, e.g. ferroelectricity colossal magnetoresistivity. A-site ordered/disordered perovskite...

Eu, Si co-doped AlN shows blue luminescence by UV and electron excitation. However, it is not clear how Eu located in a wurtzite lattice as there enough space for large cation. In the present study, analyzed to elucidate luminescent center's location role of co-dopant Si. The XRD that parameters decrease compared solely doped undoped due doping lattice. product impurity phase contamination with reddish body color. co-doping essential incorporation into AlN. TEM-EDS HAADF-STEM measurements...