High-precision quantitative atomic-site-analysis of functional dopants in crystalline materials by electron-channelling-enhanced microanalysis

Publication date: Available online 9 March 2017 Source:Progress in Crystal Growth and Characterization of Materials Author(s): Shunsuke Muto, Masahiro Ohtsuka Knowledge of the location and concentration of impurity atoms doped into a synthesized material is of great interest to investigate the effect of doping. This would usually be investigated using X-ray or neutron diffraction methods in combination with Rietveld analysis. However, this technique requires a large-scale facility such as a synchrotron radiation source and nuclear reactor, and can sometimes fail to produce the desired results, depending on the constituent elements and the crystallographic conditions that are being analysed. Thus, it would be preferable to use an element-selective spectroscopy technique that is applicable to any combination of elements. We have established a quantitative method to deduce the occupation sites and their occupancies, as well as the site-dependent chemical states of the doped elements, using a combination of transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, and electron energy-loss spectroscopy (EELS). The method is based on electron channelling phenomena where the symmetries of the Bloch waves excited in a crystal are dependent on the diffraction condition or incident beam direction with respect to the crystal axes. By rocking the incident electron beam with a fixed pivot point on the sample surface, a set of EDX/EELS spectra are obtained as a f...
Source: Progress in Crystal Growth and Characterization of Materials - Category: Chemistry Source Type: research

Related Links:

The ability to perceive differences in environmental contrast is critical for navigating complex environments safely. People with Parkinson's disease (PD) report a multitude of visual and cognitive deficits which may impede safe obstacle negotiation and in...
Source: SafetyLit - Category: International Medicine & Public Health Tags: Age: Elder Adults Source Type: news
A polygenic risk score (PRS) can help predict resistance to treatment with antipsychotic medication in schizophrenia, according to Scandinavian researchers.Reuters Health Information
Source: Medscape Medical News Headlines - Category: Consumer Health News Tags: Psychiatry News Source Type: news
Conclusions: These findings suggest that TMBs may serve as a uniquely persistent indicator of TBI and reinforce the importance of acute post-injury imaging for accurate characterization of persistent imaging findings. PMID: 32228304 [PubMed - as supplied by publisher]
Source: Brain Injury - Category: Neurology Tags: Brain Inj Source Type: research
This article will review the epidemiology of heart failure in ESRD, the pathophysiological derangements of the renin–angiotensin–aldosterone system in patients with kidney disease, and the results from case series and trials of the use of MRAs in ESRD with HFrEF. Although limited to several small trials using MRAs in peritoneal and hemodialysis patients with or without HFrEF, the current literature appears to show the potential for clinical benefits with little risk.
Source: Cardiology in Review - Category: Cardiology Tags: Review Articles Source Type: research
Authors: Mégevand P, Seeck M Abstract Introduction: Electric source imaging (ESI) refers to the estimation of the cerebral sources of electric signals recorded at the head surface using electroencephalography (EEG). Thanks to the availability of EEG systems with high numbers of electrodes and to progress in software to analyze the signals they collect, ESI can be applied to epilepsy-related pathological EEG signals like interictal spikes and seizures.Areas covered: In this narrative review, we discuss selected original research articles on the use of ESI in epilepsy patients considered for surgery. Epilepsy-...
Source: Expert Review of Medical Devices - Category: Medical Devices Tags: Expert Rev Med Devices Source Type: research
Authors: Dąbrowska E, Harazny JM, Miszkowska-Nagórna E, Stefański A, Graff B, Kunicka K, Świerblewska E, Rojek A, Szyndler A, Wolf J, Gruchała M, Schmieder RE, Narkiewicz K Abstract Purpose: In the course of hypertension, left ventricular hypertrophy and diastolic dysfunction develop very often and may progress toward heart failure. The aim of the study was to analyze the relationship between abnormalities of retinal microcirculation and cardiac damage defined as left ventricular hypertrophy and/or diastolic dysfunction.Materials and methods: The study comprised 88 patients with essential hypertension. T...
Source: Blood Pressure - Category: Hematology Tags: Blood Press Source Type: research
This study evaluated the frequency in which a hip dislocation is first diagnosed by computed tomography (CT) scan. A retrospective review was conducted of orthopaedic trauma patients presenting with hip dislocation to a Level 1 trauma center over three years. We recorded whether the patient first received pelvic radiograph (PXR) or CT scan of the pelvis, if the patient underwent closed reduction of the hip prior to CT scan, and if repeat pelvis CT scan was done. Of 83 hip dislocations, 64 patients were sent to CT scanner dislocated; 19 patients first had PXR and underwent closed reduction of the hip prior to CT scan. By ob...
Source: Journal of surgical orthopaedic advances - Category: Orthopaedics Tags: J Surg Orthop Adv Source Type: research
Conclusions: These findings indicate that good candidates for resection of metastatic tumors of PanNETs could be patients with low Ki67 tumors and a small number of metastatic tumors. PMID: 32223573 [PubMed - as supplied by publisher]
Source: Scandinavian Journal of Gastroenterology - Category: Gastroenterology Tags: Scand J Gastroenterol Source Type: research
Conclusions: Gastric cancer risk assessment using endoscopic or histologic methods provided similar results such that the absence or a mild grade of endoscopic gastric atrophy would preclude the need for histologic mapping. PMID: 32223458 [PubMed - as supplied by publisher]
Source: Scandinavian Journal of Gastroenterology - Category: Gastroenterology Tags: Scand J Gastroenterol Source Type: research
For the first time ever, the number of CT procedures in the U.S. conducted...Read more on AuntMinnie.comRelated Reading: IMV: PET scan volume continues growing at steady pace IMV: CT hits peak as users address workflow concerns IMV: MR providers work harder as procedure volume grows IMV: Global radiologists are optimistic despite local challenges IMV: Imaging boosts precision in radiation therapy
Source: AuntMinnie.com Headlines - Category: Radiology Source Type: news
More News: Chemistry | PET Scan | Statistics