Nanoscopic analysis of oxygen segregation at tilt boundaries in silicon ingots using atom probe tomography combined with TEM and ab initio calculations
Summary
We have developed an analytical method to determine the segregation levels on the same tilt boundaries (TBs) at the same nanoscopic location by a joint use of atom probe tomography and scanning transmission electron microscopy, and discussed the mechanism of oxygen segregation at TBs in silicon ingots in terms of bond distortions around the TBs. The three‐dimensional distribution of oxygen atoms was determined at the typical small‐ and large‐angle TBs by atom probe tomography with a low impurity detection limit (0.01 at.% on a TB plane) simultaneously with high spatial resolution (about 0.4 nm). The three‐d...
Source: Journal of Microscopy - July 7, 2017 Category: Laboratory Medicine Authors: Y. OHNO, K. INOUE, K. FUJIWARA, K. KUTSUKAKE, M. DEURA, I. YONENAGA, N. EBISAWA, Y. SHIMIZU, K. INOUE, Y. NAGAI, H. YOSHIDA, S. TAKEDA, S. TANAKA, M. KOHYAMA Tags: Themed Issue Paper Source Type: research
A reliable approach to prepare brittle semiconducting materials for cross ‐sectional transmission electron microscopy
Summary
Here, we present a sample preparation approach that simplifies the thinning of very brittle wide bandgap semiconducting materials in cross‐section geometry for (scanning) transmission electron microscopy. Using AlN thin films grown on sapphire and AlN substrates as case studies, we demonstrate that high‐quality samples can be routinely prepared while greatly reducing the preparation time and consumables cost. The approach removes the sample preparation barrier to studying a wide variety of materials by electron microscopy.
Lay description
Here we present a sample preparation approach that simplifies the thinnin...
Source: Journal of Microscopy - July 7, 2017 Category: Laboratory Medicine Authors: J. H. DYCUS, J. M. LEBEAU Tags: Themed Issue Paper Source Type: research
Reconstruction of 3D grain boundaries from rock thin sections, using an advanced polarised ‐light microscopy method
Summary
Grain boundaries play a significant role in materials by initiating reactions and collecting impurities. Here we present FAGO (Fabric Analyser Grain boundary recOnstruction), a first step towards the automatic determination of three‐dimensional (3D) grain boundary geometry using polarised light. The trace of the grain boundaries from 2D rock thin sections are determined primarily from data acquired using an automatic fabric analyser microscope and the FAME software (fabric analyser‐based microstructure evaluation; Peternell and colleagues and Hammes and Peternell). Based on the Fabric Analyser G50's unique arra...
Source: Journal of Microscopy - July 1, 2017 Category: Laboratory Medicine Authors: D.M. HAMMES, M. PETERNELL Tags: Original Article Source Type: research
Study of the surfactant role in latex –aerogel systems by scanning transmission electron microscopy on aqueous suspensions
Summary
For insulation applications, boards thinner than 2 cm are under design with specific thermal conductivities lower than 15 mW m−1 K−1. This requires binding slightly hydrophobic aerogels which are highly nanoporous granular materials. To reach this step and ensure insulation board durability at the building scale, it is compulsory to design, characterise and analyse the microstructure at the nanoscale. It is indeed necessary to understand how the solid material is formed from a liquid suspension. This issue is addressed in this paper through wet‐STEM experiments carried out in an Environmental Scanning Elect...
Source: Journal of Microscopy - July 1, 2017 Category: Laboratory Medicine Authors: A. PERRET, G. FORAY, K. MASENELLI ‐VARLOT, E. MAIRE, B. YRIEIX Tags: Original Article Source Type: research
3 ‐D microstructure of olivine in complex geological materials reconstructed by correlative X‐ray μ‐CT and EBSD analyses
Summary
We reconstruct the 3‐D microstructure of centimetre‐sized olivine crystals in rocks from the Almirez ultramafic massif (SE Spain) using combined X‐ray micro computed tomography (‐CT) and electron backscatter diffraction (EBSD). The semidestructive sample treatment involves geographically oriented drill pressing of rocks and preparation of oriented thin sections for EBSD from the ‐CT scanned cores. The ‐CT results show that the mean intercept length (MIL) analyses provide reliable information on the shape preferred orientation (SPO) of texturally different olivine groups. We show that statistical interpr...
Source: Journal of Microscopy - July 1, 2017 Category: Laboratory Medicine Authors: W. ‐A. KAHL, N. DILISSEN, K. HIDAS, C. J. GARRIDO, V. LÓPEZ‐SÁNCHEZ‐VIZCAÍNO, M. J. ROMÁN‐ALPISTE Tags: Original Article Source Type: research
Direct observations of dynamic PtCo interactions in fuel cell catalyst precursors at the atomic level using E(S)TEM
Summary
Reduction reactions in practical bimetallic platinum–cobalt electrode catalyst precursors containing platinum, cobalt and cobalt oxides in hydrogen at 200, 450 and 700 °C for 6 h have been studied in situ using an aberration corrected environmental (scanning) transmission electron microscope (AC E(S)TEM). Little difference was observed in reduction at 200 °C but during and after reduction at 450 °C, small nanoparticles less than 3 nm in diameter with tetragonal PtCo structures were observed and limited Pt3Co ordering could be seen on the surfaces of larger nanoparticles. During and after reduction at 700 °C, ...
Source: Journal of Microscopy - July 1, 2017 Category: Laboratory Medicine Authors: M.R. WARD, B. THEOBALD, J. SHARMAN, E.D. BOYES, P.L. GAI Tags: Themed Issue Paper Source Type: research
Retrieving overlapping crystals information from TEM nano ‐beam electron diffraction patterns
Summary
The diffraction patterns acquired with a transmission electron microscope (TEM) contain Bragg reflections related to all the crystals superimposed in the thin foil and crossed by the electron beam. Regarding TEM‐based orientation and phase characterisation techniques, the nondissociation of these signals is usually considered as the main limitation for the indexation of diffraction patterns. A new method to identify the information related to the distinct but overlapped grains is presented. It consists in subtracting the signature of the dominant crystal before reindexing the diffraction pattern. The method is co...
Source: Journal of Microscopy - July 1, 2017 Category: Laboratory Medicine Authors: A. VALERY, E. F. RAUCH, L. CL ÉMENT, F. LORUT Tags: Original Article Source Type: research
Utilization of integrated correlative light and electron microscopy (iCLEM) for imaging sedimentary organic matter
We report here a new microscopic technique for imaging and identifying sedimentary organic matter in geologic materials that combines inverted fluorescence microscopy with scanning electron microscopy and allows for sequential imaging of the same region of interest without transferring the sample between instruments. This integrated correlative light and electron microscopy technique is demonstrated with observations from an immature lacustrine oil shale from the Eocene Green River Mahogany Zone and mid‐oil window paralic shale from the Upper Cretaceous Tuscaloosa Group. This technique has the potential to allow for iden...
Source: Journal of Microscopy - June 30, 2017 Category: Laboratory Medicine Authors: PAUL C. HACKLEY, BRETT J. VALENTINE, LENARD M. VOORTMAN, DAAN S.B. VAN OOSTEN SLINGELAND, JAVIN HATCHERIAN Tags: Original Article Source Type: research
Pontamine fast scarlet 4B bifluorescence and measurements of cellulose microfibril angles
In this study, we have investigated the properties of a fluorescent dye, pontamine fast scarlet 4B, that binds specifically to cellulose. As this dye only will absorb light, and thus fluoresce, when it is oriented parallel to the polarisation of light, any variations that occur in fluorescence when the polarisation of the excitation light is changed will reveal structural information about the orientation of cellulose within the cell wall. We modulated the relative polarisation of the excitation light in two ways, either by physically rotating the sample through a plane polarised laser (part of a confocal microscope), or b...
Source: Journal of Microscopy - June 27, 2017 Category: Laboratory Medicine Authors: J. THOMAS, N.A. IDRIS, D.A. COLLINGS Tags: Original Article Source Type: research
Imprint cytology ‐based breast malignancy screening: an efficient nuclei segmentation technique
This study introduces computer assisted BC detection using IC images perhaps for the first time. The proposed approach could offer benefit to the pathologists for confirmatory BC screening especially in overlapping nuclei cases and could potentially lead to a better shape understanding of malignant nuclei. (Source: Journal of Microscopy)
Source: Journal of Microscopy - June 27, 2017 Category: Laboratory Medicine Authors: M. SAHA, I. ARUN, S. AGARWAL, R. AHMED, S. CHATTERJEE, C. CHAKRABORTY Tags: Original Article Source Type: research
Wear mechanisms of the biotribological nanocomposite a ‐C : H coatings implanted by metallic nanoparticles
Summary
Recently, to reduce the residual stress and increase the mechanical properties of a‐C:H coatings, metallic nanoparticles have been implanted into their structure. In the present work, to improve the properties of the coating, metallic nanoparticles, including Cu, Nb, Ta, Zr, AgPt and Ag, were inserted into the a‐C:H structure. The applied biological and mechanical analysis allowed the optimal biotribological parameters to be indicated for the potential application as protective coatings for metallic medical tools. Wear mechanisms operating at the small length of the designed biotribological coating, such as a...
Source: Journal of Microscopy - June 14, 2017 Category: Laboratory Medicine Authors: L. MAJOR, M. JANUSZ, J.M. LACKNER, M. KOT, M. DYNER, B. MAJOR Tags: Original Article Source Type: research
Evaluation of five diffeomorphic image registration algorithms for mouse brain magnetic resonance microscopy
In this study, we specially tuned five diffeomorphic image registration algorithms [DARTEL, geodesic shooting, diffeo‐demons, SyN (Greedy‐SyN and geodesic‐SyN)] for mouse brain MRMs and evaluated their performance using three measures [volume overlap percentage (VOP), residual intensity error (RIE) and surface concordance ratio (SCR)]. Geodesic‐SyN performed significantly better than the other methods according to all three different measures. These findings are important for the studies on structural brain changes that may occur in wild‐type and transgenic mouse brains.
Lay description
Nowadays, the animal mode...
Source: Journal of Microscopy - June 14, 2017 Category: Laboratory Medicine Authors: ZHENRONG FU, LAN LIN, MIAO TIAN, JINGXUAN WANG, BAIWEN ZHANG, PINGPING CHU, SHAOWU LI, MUHAMMAD MOHSIN PATHAN, YULIN DENG, SHUICAI WU Tags: Original Article Source Type: research
AutoIHC ‐scoring: a machine learning framework for automated Allred scoring of molecular expression in ER‐ and PR‐stained breast cancer tissue
Summary
In prognostic evaluation of breast cancer Immunohistochemical (IHC) markers namely, oestrogen receptor (ER) and progesterone receptor (PR) are widely used. The expert pathologist investigates qualitatively the stained tissue slide under microscope to provide the Allred score; which is clinically used for therapeutic decision making. Such qualitative judgment is time‐consuming, tedious and more often suffers from interobserver variability. As a result, it leads to imprecise IHC score for ER and PR. To overcome this, there is an urgent need of developing a reliable and efficient IHC quantifier for high throughput d...
Source: Journal of Microscopy - June 14, 2017 Category: Laboratory Medicine Authors: S. TEWARY, I. ARUN, R. AHMED, S. CHATTERJEE, C. CHAKRABORTY Tags: Original Article Source Type: research
TOC ‐ Issue Information
(Source: Journal of Microscopy)
Source: Journal of Microscopy - June 14, 2017 Category: Laboratory Medicine Tags: Issue Information Source Type: research
Candida albicans biofilms: comparative analysis of room ‐temperature and cryofixation for scanning electron microscopy
Summary
Biofilms are frequently related to invasive fungal infections and are reported to be more resistant to antifungal drugs than planktonic cells. The structural complexity of the biofilm as well as the presence of a polymeric extracellular matrix (ECM) is thought to be associated with this resistant behavior. Scanning electron microscopy (SEM) after room temperature glutaraldehyde‐based fixation, have been used to study fungal biofilm structure and drug susceptibility but they usually fail to preserve the ECM and, therefore, are not an optimised methodology to understand the complexity of the fungal biofilm. Thus, i...
Source: Journal of Microscopy - June 1, 2017 Category: Laboratory Medicine Authors: T. VILA, B.B. FONSECA, M.M.L. DA CUNHA, G.R.C. DOS SANTOS, K. ISHIDA, E. BARRETO ‐BERGTER, W. DE SOUZA, S. ROZENTAL Tags: Original Article Source Type: research
