scholarly journals Crystals from the Powellite-Scheelite Series at the Nanoscale: A Case Study from the Zhibula Cu Skarn, Gangdese Belt, Tibet

Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 340 ◽  
Author(s):  
Jing Xu ◽  
Cristiana L. Ciobanu ◽  
Nigel J. Cook ◽  
Ashley Slattery
Keyword(s):  
Solid Solution ◽  
Rare Earth ◽  
Inductively Coupled Plasma ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Growth Direction ◽  
Dark Field ◽  
Atomic Scale ◽  
Oscillatory Zoning ◽  
Compositional Range

Scheelite (CaWO4) and powellite (CaMoO4) are isostructural minerals considered as a non-ideal solid solution series. Micron- to nanoscale investigation of a specimen of skarnoid from Zhibula, Gangdese Belt, Tibet, China, was carried out to assess the identity of the phases within a broad scheelite-powellite (Sch-Pow) compositional range, and to place additional constraints on redox changes during ore formation. An electron probe microanalysis shows that Mo-rich domains within complex oscillatory-zoned single crystals, and as thin sliver-like domains, have a compositional range from 20 mol.% to 80 mol.% Pow. These occur within a matrix of unzoned, close-to-end-member scheelite aggregates (87 mol.%–95 mol.% Sch). Laser-ablation inductively coupled plasma mass spectrometry spot analysis and element mapping reveal systematic partitioning behaviour of trace elements in skarn minerals (grossular50, diopside80, anorthite, and retrograde clinozoisite) and scheelite-powellite aggregates. The Mo-rich domains feature higher concentrations of As, Nb, and light rare earth elements LREE, whereas W-rich domains are comparatively enriched in Y and Sr. Transmission electron microscopy (TEM) was carried out on focused-ion-beam-prepared foils extracted in situ from domains with oscillatory zoning occurring as slivers of 20 mol.%–40 mol.% Pow and 48 mol.%–80 mol.% Pow composition within an unzoned low-Mo matrix (20 mol.% Pow). Electron diffractions, high-angular annular dark field (HAADF) scanning-TEM (STEM) imaging, and energy-dispersive spectroscopy STEM mapping show chemical oscillatory zoning with interfaces that have continuity in crystal orientation throughout each defined structure, zoned grain or sliver. Non-linear thermodynamics likely govern the patterning and presence of compositionally and texturally distinct domains, in agreement with a non-ideal solid solution. We show that the sharpest compositional contrasts are also recognisable by variation in growth direction. Atomic-scale resolution imaging and STEM simulation confirm the presence of scheelite-powellite within the analysed range (20 mol.%–80 mol.% Pow). Xenotime-(Y) inclusions occur as nm-wide needles with epitaxial orientation to the host scheelite-powellite matrix throughout both types of patterns, but no discrete Mo- or W-bearing inclusions are observed. The observed geochemical and petrographic features can be reconciled with a redox model involving prograde deposition of a scheelite+molybdenite assemblage (reduced), followed by interaction with low-T fluids, leading to molybdenite dissolution and reprecipitation of Mo as powellite-rich domains (retrograde stage, oxidised). The observation of nanoscale inclusions of xenotime-(Y) within scheelite carries implications for the meaningful interpretation of petrogenesis based on rare earth element (REE) concentrations and fractionation patterns. This research demonstrates that HAADF-STEM is a versatile technique to address issues of solid solution and compositional heterogeneity.

Fast Turn-around Failure Analysis of Metal Interconnection Using FIB and LA ICP-MS

2010 ◽  
Author(s):  
Zixiao Pan ◽  
Wei Wei ◽  
Fuhe Li
Keyword(s):  
Failure Analysis ◽  
Inductively Coupled Plasma ◽  
Structural Damage ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Detection Sensitivity ◽  
Chemical Contamination ◽  
Inductively Coupled ◽  
Minimal Sample ◽  
Icp Ms

Abstract This paper introduces our effort in failure analysis of a 200 nm thick metal interconnection on a glass substrate and covered with a passivation layer. Structural damage in localized areas of the metal interconnections was observed with the aid of focused ion beam (FIB) cross-sectioning. Laser ablation inductively coupled plasma mass spectroscopy (LA ICP-MS) was then applied to the problematic areas on the interconnection for chemical survey. LA ICP-MS showed direct evidence of localized chemical contamination, which has likely led to corrosion (or over-etching) of the metal interconnection and the assembly failure. Due to the high detection sensitivity of LA ICP-MS and its compatibility with insulating material analysis, minimal sample preparation is required. As a result, the combination of FIB and LA ICP-MS enabled successful meso-scale failure analysis with fast turnaround and reasonable cost.

Optimizing Gas-Assisted Processes for Ga and Xe FIB Circuit Edit Application

2016 ◽  
Author(s):  
Valery Ray ◽  
Josef V. Oboňa ◽  
Sharang Sharang ◽  
Lolita Rotkina ◽  
Eddie Chang ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Structural Damage ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam Width ◽  
Ion Source ◽  
Reconstruction Technique ◽  
Beam Diameter ◽  
Current Profile ◽  
Single Beam

Abstract Despite commercial availability of a number of gas-enhanced chemical etches for faster removal of the material, there is still lack of understanding about how to take into account ion implantation and the structural damage by the primary ion beam during focused ion beam gas-assisted etching (FIB GAE). This paper describes the attempt to apply simplified beam reconstruction technique to characterize FIB GAE within single beam width and to evaluate the parameters critical for editing features with the dimensions close to the effective ion beam diameter. The approach is based on reverse-simulation methodology of ion beam current profile reconstruction. Enhancement of silicon dioxide etching with xenon difluoride precursor in xenon FIB with inductively coupled plasma ion source appears to be high and relatively uniform over the cross-section of the xenon beam, making xenon FIB potentially suitable platform for selective removal of materials in circuit edit application.

scholarly journals Avoiding Dendrite Formation by Confining Lithium Deposition Underneath Li-Sn Coatings

2020 ◽  
Author(s):  
Grace Whang ◽  
Qizhang Yan ◽  
Da Li ◽  
Ziyang Wei ◽  
Danielle M. Butts ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Research Direction ◽  
Exchange Current ◽  
Atomic Scale ◽  
Interfacial Layers ◽  
Dendrite Formation ◽  
Lithium Deposition ◽  
Lithium Dendrite

<p>The use of interfacial layers to stabilize the lithium surface is a popular research direction for improving the morphology of deposited lithium and suppressing lithium dendrite formation. This work considers a different approach to controlling dendrite formation where lithium is plated underneath an interfacial coating. In the present research, a Li-Sn intermetallic was chosen as a model system due to its lithium-rich intermetallic phases and high Li diffusivity. These coatings also exhibit a significantly higher Li exchange current than bare Li thus leading to better charge transfer kinetics. The exchange current is instrumental in determining whether lithium deposition occurs above or below the Li-Sn coating. High-resolution transmission electron microscopy and cryogenic focused ion beam scanning electron microscopy were used to identify the features associated with Li deposition. Atomic scale simulations provide insight as to the adsorption energies determining the deposition of lithium below the Li-Sn coating. </p>

Atomic-scale thermocapillary flow in focused ion beam milling

2015 ◽  
Vol 27 (5) ◽  
pp. 052003 ◽  
Author(s):  
K. Das ◽  
H. T. Johnson ◽  
J. B. Freund
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Thermocapillary Flow ◽  
Atomic Scale ◽  
Focused Ion Beam Milling

Point Defect Clusters and Dislocations in FIB Irradiated Nanocrystalline Aluminum Films: An Electron Tomography and Aberration-Corrected High-Resolution ADF-STEM Study

2011 ◽  
Vol 17 (6) ◽  
pp. 983-990 ◽  
Author(s):  
Hosni Idrissi ◽  
Stuart Turner ◽  
Masatoshi Mitsuhara ◽  
Binjie Wang ◽  
Satoshi Hata ◽  
...  
Keyword(s):  
High Resolution ◽  
Point Defect ◽  
Focused Ion Beam ◽  
Electron Tomography ◽  
Ion Beam ◽  
Dark Field ◽  
Internal Stresses ◽  
Defect Clusters ◽  
Point Defect Clusters ◽  
Aberration Corrected

AbstractFocused ion beam (FIB) induced damage in nanocrystalline Al thin films has been characterized using advanced transmission electron microscopy techniques. Electron tomography was used to analyze the three-dimensional distribution of point defect clusters induced by FIB milling, as well as their interaction with preexisting dislocations generated by internal stresses in the Al films. The atomic structure of interstitial Frank loops induced by irradiation, as well as the core structure of Frank dislocations, has been resolved with aberration-corrected high-resolution annular dark-field scanning TEM. The combination of both techniques constitutes a powerful tool for the study of the intrinsic structural properties of point defect clusters as well as the interaction of these defects with preexisting or deformation dislocations in irradiated bulk or nanostructured materials.

The Release of Incidental Nanoparticles During the Weathering of Gunshot Residue in Soils of a Shooting Range in Ontario, Canada

2020 ◽  
Author(s):  
Michael Schindler ◽  
Keegan Weatherhead ◽  
Haley Mantha
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Fine Particulate Matter ◽  
Mineralogical Composition ◽  
Gunshot Residue ◽  
Detailed Knowledge ◽  
Shooting Range ◽  
Colloidal Fraction

Abstract Gunshot residue is emitted as fine particulate matter upon the ignition of percussion-sensitive explosives among other additives in a firearm barrel. The particulates condense from a vapor phase and contain material from the Pb-Sb-Ba-bearing primer, S-bearing gunpowder, and the Pb-bearing bullet fragments. Shooters can inhale or ingest the fine particulates which also attach to their hands, clothing, and other surfaces. Estimation of the bioavailability of the emitted toxic Pb- and Sb-bearing particulates requires detailed knowledge of their mineralogical composition and those of their weathering products. For this purpose, gunshot residue particulates have been collected from soils in front of a firing line of a shooting range in Ontario, Canada. Bulk mineralogical and chemical features of the soils have been characterized using X-ray powder diffraction, inductively coupled plasma-mass spectrometry, and scanning electron microscopy. The focused ion-beam technique has been used to extract a section containing numerous altered gunshot residue particulates from a soil grain. Subsequent transmission electron microscopy shows for the first time that gunshot residue particulates are composed of metallic δ-Pb, α-Sb, galena (PbS), and an unidentified Ba-bearing phase. Weathering of the gunshot residue particulates results in the formation of incidental nanoparticles (i.e., not purposely engineered to occur at the nanometer scale) in the form of δ-Pb, massicot, PbO, and galena. The formation and mobilization of some of these nanoparticles within the soil grain suggest that their release during the weathering of bullets and gunshot residue contributes to the release of Pb into the environment. Hydrocerussite, Pb3(CO3)2(OH)2, cerussite, PbCO3, and massicot and anglesite, PbSO4, are the major secondary Pb-phases in and around altered GSR particulates. These phases form during the weathering of metallic Pb, massicot, and galena nanoparticles in a Ca-carbonate rich environment. Secondary Sb-bearing phases are valentinite, Sb2O3, and amorphous Sb-Pb phases (Sb:Pb ratio = 2:1–4:1). The latter phases have partially replaced large proportions of the Ca-carbonates surrounding the gunshot residue particulates. The larger abundance of the amorphous Sb-Pb phases relative to valentinite suggests that their solubility most likely controls the release of Sb into the bulk soil. The SEM and TEM characterizations and chemical analyses of mineral surface coatings and the colloidal fraction of a leachate from the collected surficial soils indicate that Pb occurs predominantly in the colloidal fraction, is often associated with sulfate-bearing colloids, and is sequestered in sulfate and carbonate/hydroxide coatings.

Field mapping of focused ion beam prepared semiconductor devices by off-axis and dark field electron holography

2013 ◽  
Vol 28 (12) ◽  
pp. 125013 ◽  
Author(s):  
David Cooper ◽  
Pierrette Rivallin ◽  
Georges Guegan ◽  
Christophe Plantier ◽  
Eric Robin ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Semiconductor Devices ◽  
Dark Field ◽  
Electron Holography ◽  
Field Mapping ◽  
Field Electron ◽  
Dark Field Electron

TEM Investigations of Damage Caused by Indentation of Multilayer TiN/Ti/a-C-H Coatings

2012 ◽  
Vol 186 ◽  
pp. 188-191
Author(s):  
Łukasz Major
Keyword(s):  
Focused Ion Beam ◽  
Mechanical Test ◽  
Ion Beam ◽  
Growth Direction ◽  
Metallic Phase ◽  
Energetic Cost ◽  
Multilayer Coatings ◽  
Static Test ◽  
Thin Foils ◽  
Diffraction Patterns

The effect of damage on microstructure of multilayer coatings (TiN/Ti/a-C:H) have been analyzed. They were deposited through Pulsed Laser Deposition technique (PLD). The coatings microstructure was characterized using TECNAI F20 (200kV) FEG. The phase and chemical composition were described by EDS (Energy Dispersive X-Ray Spectroscopy) and electron diffraction patterns respectively. Coatings damage resistance was tested by pushing diamond ball with 1N of the applied load (static test). Thin foils were prepared directly from the wear track by focused ion beam method (FIB) using QUANTA 200 3D DualBeam. The multilayer coatings were characterized by strongly dislocated microstructure in TiN layers (like in single layered TiN), while a-C:H were amorphous. After mechanical test the multilayer TiN/Ti/a-C:H coating was strongly deformed. Ceramic TiN and a-C:H layers showed brittle cracking, while very thin metallic Ti layers (presented at each interface) deformed plastically. Deformation lines were propagating in 450 to crystalline growth direction. The wear of crystalline TiN layers caused cracks along {111} planes. The presence of metallic phase lead to the cracking resistance properties increase and the increase an energetic cost of propagating cracks.

Microstructural Observation of Focused Ion Beam Modification of Ni Silicide/Si Thin Films

1996 ◽  
Vol 439 ◽  
Author(s):  
Miyoko Tanaka ◽  
Kazuo Furuya ◽  
Tetsuya Saito
Keyword(s):  
Structural Changes ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Dark Field ◽  
In Situ Tem ◽  
Si Substrate ◽  
Ion Beam Modification ◽  
Surrounding Matrix ◽  
Transmission Electron

AbstractFocused ion beam (FIB) irradiation of a thin Ni2Si layer deposited on a Si substrate was carried out and studied using an in-situ transmission electron microscope (in-situ TEM). Square areas on sides of 4 by 4 and 9 by 9 μm were patterned at room temperature with a 25keV Ga+-FIB attached to the TEM. The structural changes of the films indicate a uniform milling; sputtering of the Ni2Si layer and the damage introducing to the Si substrate. Annealing at 673 K results in the change of the Ni2Si layer into an epitaxial NiSi2 layer outside the FIB irradiated area, but several precipitates appear around the treated area. Precipitates was analyzed by energy dispersive X-ray spectroscopy (EDS). Larger amount of Ni than the surrounding matrix was found in precipitates. Selected area diffraction (SAD) patterns of the precipitates and the corresponding dark field images imply the formation of a Ni rich silicide. The relation between the FIB tail and the precipitation is indicated.

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