Miscibility Gap Closure, Interface Morphology, and Phase Microstructure of 3D LixFePO4 Nanoparticles from Surface Wetting and Coherency Strain

Interpretation of fine-scale microstructures containing high volume fractions of second phase is complex. In particular, microstructures developed through decomposition within low temperature miscibility gaps may be extremely fine. This paper compares the morphological interpretations of such complex microstructures by the high-resolution techniques of TEM and atom probe field-ion microscopy (APFIM).The Fe-25 at% Be alloy selected for this study was aged within the low temperature miscibility gap to form a <100> aligned two-phase microstructure. This triaxially modulated microstructure is composed of an Fe-rich ferrite phase and a B2-ordered Be-enriched phase. The microstructural characterization through conventional bright-field TEM is inadequate because of the many contributions to image contrast. The ordering reaction which accompanies spinodal decomposition in this alloy permits simplification of the image by the use of the centered dark field technique to image just one phase. A CDF image formed with a B2 superlattice reflection is shown in fig. 1. In this CDF micrograph, the the B2-ordered Be-enriched phase appears as bright regions in the darkly-imaging ferrite. By examining the specimen in a [001] orientation, the <100> nature of the modulations is evident.

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Interface morphology of thermal oxide grown on polycrystalline silicon by different processes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100131619 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1396-1397

Author(s):

H. Yen ◽

E. P. Kvam ◽

R. Bashir ◽

S. Venkatesan ◽

G. W. Neudeck

Keyword(s):

Integrated Circuits ◽

Polycrystalline Silicon ◽

Silicon Films ◽

Interface Morphology ◽

Oxide Interface ◽

Poly Silicon ◽

Thermal Oxide ◽

Grain Orientations ◽

Polycrystalline Silicon Films ◽

P Type

Polycrystalline silicon, when highly doped, is commonly used in microelectronics applications such as gates and interconnects. The packing density of integrated circuits can be enhanced by fabricating multilevel polycrystalline silicon films separated by insulating SiO2 layers. It has been found that device performance and electrical properties are strongly affected by the interface morphology between polycrystalline silicon and SiO2. As a thermal oxide layer is grown, the poly silicon is consumed, and there is a volume expansion of the oxide relative to the atomic silicon. Roughness at the poly silicon/thermal oxide interface can be severely deleterious due to stresses induced by the volume change during oxidation. Further, grain orientations and grain boundaries may alter oxidation kinetics, which will also affect roughness, and thus stress.Three groups of polycrystalline silicon films were deposited by LPCVD after growing thermal oxide on p-type wafers. The films were doped with phosphorus or arsenic by three different methods.

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Transition alpha structure in beta-isomorphous Nb-Hf alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126068 ◽

1987 ◽

Vol 45 ◽

pp. 232-233

Author(s):

R.W. Carpenter ◽

Changhai Li ◽

David J. Smith

Keyword(s):

Solid Solution ◽

Solution Phase ◽

Miscibility Gap ◽

Large Strains ◽

Solid Solution Phase ◽

Two Phase ◽

Diffuse Intensity ◽

Metastable Form ◽

The Matrix ◽

Equilibrium Morphology

Binary Nb-Hf alloys exhibit a wide bcc solid solution phase field at temperatures above the Hfα→ß transition (2023K) and a two phase bcc+hcp field at lower temperatures. The β solvus exhibits a small slope above about 1500K, suggesting the possible existence of a miscibility gap. An earlier investigation showed that two morphological forms of precipitate occur during the bcc→hcp transformation. The equilibrium morphology is rod-type with axes along <113> bcc. The crystallographic habit of the rod precipitate follows the Burgers relations: {110}||{0001}, <112> || <1010>. The earlier metastable form, transition α, occurs as thin discs with {100} habit. The {100} discs induce large strains in the matrix. Selected area diffraction examination of regions ∼2 microns in diameter containing many disc precipitates showed that, a diffuse intensity distribution whose symmetry resembled the distribution of equilibrium α Bragg spots was associated with the disc precipitate.

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Progressive Debonding of Multilayer Interconnect Structures

MRS Proceedings ◽

10.1557/proc-473-21 ◽

1997 ◽

Vol 473 ◽

Cited By ~ 9

Author(s):

Michael Lane ◽

Robert Ware ◽

Steven Voss ◽

Qing Ma ◽

Harry Fujimoto ◽

...

Keyword(s):

Thin Films ◽

Crack Growth ◽

Driving Force ◽

Adhesion Energy ◽

Time Dependent ◽

Multilayer Thin Films ◽

Processing Conditions ◽

Interface Morphology ◽

Entire Sample ◽

Crack Growth Velocity

ABSTRACTProgressive (or time dependent) debonding of interfaces poses serious problems in interconnect structures involving multilayer thin films stacks. The existence of such subcriticai debonding associated with environmentally assisted crack-growth processes is examined for a TiN/SiO2 interface commonly encountered in interconnect structures. The rate of debond extension is found to be sensitive to the mechanical driving force as well as the interface morphology, chemistry, and yielding of adjacent ductile layers. In order to investigate the effect of interconnect structure, particularly the effect of an adjacent ductile Al-Cu layer, on subcriticai debonding along the TiN/SiO2 interface, a set of samples was prepared with Al-Cu layer thicknesses varying from 0.2–4.0 μm. All other processing conditions remained the same over the entire sample run. Results showed that for a given crack growth velocity, the debond driving force scaled with Al-Cu layer thickness. Normalizing the data by the critical adhesion energy allowed a universal subcriticai debond rate curve to be derived.

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Textile fabrics. Determination of resistance to surface wetting (spray test)

10.3403/30219203u ◽

2015 ◽

Keyword(s):

Surface Wetting ◽

Textile Fabrics

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Novel Co-Cu-Based Immiscible Medium-Entropy Alloys with Promising Mechanical Properties

Metals ◽

10.3390/met11020238 ◽

2021 ◽

Vol 11 (2) ◽

pp. 238

Author(s):

Sujung Son ◽

Jongun Moon ◽

Hyeonseok Kwon ◽

Peyman Asghari Rad ◽

Hidemi Kato ◽

...

Keyword(s):

Mechanical Properties ◽

Binary System ◽

Design Methodology ◽

Miscibility Gap ◽

Face Centered Cubic ◽

Solid Solution Strengthening ◽

Solution Strengthening ◽

Face Centered ◽

Strength And Ductility ◽

Cobalt Copper

New AlxCo50−xCu50−xMnx (x = 2.5, 10, and 15 atomic %, at%) immiscible medium-entropy alloys (IMMEAs) were designed based on the cobalt-copper binary system. Aluminum, a strong B2 phase former, was added to enhance yield strength and ultimate tensile strength, while manganese was added for additional solid solution strengthening. In this work, the microstructural evolution and mechanical properties of the designed Al-Co-Cu-Mn system are examined. The alloys exhibit phase separation into dual face-centered cubic (FCC) phases due to the miscibility gap of the cobalt-copper binary system with the formation of CoAl-rich B2 phases. The hard B2 phases significantly contribute to the strength of the alloys, whereas the dual FCC phases contribute to elongation mitigating brittle fracture. Consequently, analysis of the Al-Co-Cu-Mn B2-strengthened IMMEAs suggest that the new alloy design methodology results in a good combination of strength and ductility.

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Influence of Mg loss on the phase stability in Mg2X (X = Si, Sn) and its correlation with coherency strain

Acta Materialia ◽

10.1016/j.actamat.2021.116737 ◽

2021 ◽

Vol 208 ◽

pp. 116737 ◽

Cited By ~ 1

Author(s):

Mohammad Yasseri ◽

Kunal Mitra ◽

Aryan Sankhla ◽

Johannes de Boor ◽

Eckhard Müller

Keyword(s):

Phase Stability ◽

Coherency Strain

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Phase separation of binary mixtures induced by soft centrifugal fields

Physical Chemistry Chemical Physics ◽

10.1039/d0cp01527j ◽

2021 ◽

Author(s):

Thomas Zemb ◽

Rose Rosenberg ◽

Stjepan Marčelja ◽

Dirk Haffke ◽

Jean-François Dufrêche ◽

...

Keyword(s):

Phase Separation ◽

Critical Point ◽

Binary Mixtures ◽

Liquid Mixture ◽

Model System ◽

Binary Liquid Mixture ◽

Miscibility Gap ◽

Critical Fluctuations ◽

Binary Liquid

We use the model system ethanol–dodecane to demonstrate that giant critical fluctuations induced by easily accessible weak centrifugal fields as low as 2000g can be observed above the miscibility gap even far from the critical point of a binary liquid mixture.

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