Morphological evolution of nanometer-sized BaTiO3 particles

1996 ◽  
Vol 54 ◽  
pp. 676-677
Author(s):  
C. M. Chun ◽  
A. Navrotsky ◽  
I. A. Aksay
Keyword(s):  
Heat Treatment ◽  
Colloidal Stability ◽  
Morphological Evolution ◽  
Titanium Isopropoxide ◽  
Precipitate Size ◽  
Hydrothermal Conditions ◽  
Process Step ◽  
Polyhedral Particles ◽  
Single Process ◽  
Single Process Step

Highly pure, stoichiometric, nanometer-sized, and fairly monodispersed anhydrous crystalline BaTiO3 particles are synthesized under hydrothermal conditions in a single process step without further heat treatment by reacting titanium isopropoxide [Ti(OC3H7)4] precursor in aqueous solutions of Ba(OH)2 at 80°C. Traditional considerations of solution hydrolysis, solute condensation, and nucleation only partly explain the generation of the “raspberry-like” BaTiO3 particles composed of 5∼10 nm primary crystalline particles. Consequently, the colloidal interaction of the precipitating particles and, therefore, controlled aggregation of freshly nucleated particles must be taken into account. Our TEM studies show aggregation growth of small subunits to form uniform, rounded polyhedral particles, suggesting colloidal stability may play a key role in controlling precipitate size and shape.In order to investigate the evidence supporting the aggregation growth, Ti(OC3H7)4 precursor (Aldrich) has been added to l.OM Ba(OH)2 solution and hydrothermally reacted at 80°C in polyethylene bottles. Four molecules of water and two hydroxyl ions attach through their oxygen atoms to the titanium of Ti(OC3H7)4 in a nucleophilic process.

Application of Tem on Sub-Half Micron Semiconductor Devices

1998 ◽  
Vol 523 ◽  
Author(s):  
Hong Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Failure Analysis ◽  
Process Evaluation ◽  
Semiconductor Devices ◽  
Single Source ◽  
Process Step ◽  
Transmission Electron ◽  
Single Process ◽  
Single Process Step

AbstractApplication of transmission electron microscopy on sub-half micron devices has been illustrated in terms of process evaluation and failure analysis. For process evaluation, it is emphasized that a large number of features need to be examined in order to have reliable conclusions about the processes, while for failure analysis, the goal is to pin-point a single process step causing failure or a single source introducing the particle defect.

Advanced Anodic Bonding Processes For MEMS Applications

2003 ◽  
Vol 782 ◽  
Author(s):  
V. Dragoi ◽  
P. Lindner ◽  
T. Glinsner ◽  
M. Wimplinger ◽  
S. Farrens
Keyword(s):  
Three Dimensional ◽  
Anodic Bonding ◽  
Process Conditions ◽  
Wafer Level ◽  
Process Step ◽  
Packaging Process ◽  
Powerful Technique ◽  
Wafer Level Packaging ◽  
Single Process ◽  
Single Process Step

ABSTRACTAnodic bonding is a powerful technique used in MEMS manufacturing. This process is applied mainly for building three-dimensional structures for microfluidic applications or for wafer level packaging. Process conditions will be evaluated in present paper. An experimental solution for bonding three wafers in one single process step (“triple-stack bonding”) will be introduced.

Investigation of Material Combinations Processed via Two-Component Metal Injection Moulding (2C-MIM)

2012 ◽  
Vol 727-728 ◽  
pp. 248-253 ◽  
Author(s):  
Gabriel Benedet Dutra ◽  
Marco Mulser ◽  
Roger Calixto ◽  
Frank Petzoldt
Keyword(s):  
Optical Microscopy ◽  
Injection Moulding ◽  
Interface Layer ◽  
Chemical Compositions ◽  
Interface Quality ◽  
Process Step ◽  
Metal Injection Moulding ◽  
Two Component ◽  
Single Process ◽  
Single Process Step

Joining materials with different properties into a single component is an attractive solution that allows producing parts with unique properties. In this respect, Two-Component Metal Injection Moulding (2C-MIM) presents numerous advantages, since the moulding and joining stage are performed in a single process step. In this work, the challenges, which occur when different materials are combined, are elucidated. Furthermore, the contact between metals with unequal chemical compositions leads to atomic interdiffusion that forms an interface layer. The interface quality is crucial to the production of intact parts after processing. Different material combinations are co-sintered and the interfaces are characterized by means of optical microscopy and EDX/SEM line scans. Further, thermodynamic and kinetic simulations are used to examine the interdiffusion in detail. The results show promising possibilities to combine different materials and helpful methods to examine the interface.

Thermocapillary Patterning of Nanoscale Polymer Films

2009 ◽  
Vol 1179 ◽  
Author(s):  
Mathias Dietzel ◽  
Sandra M Troian
Keyword(s):  
Surface Tension ◽  
Finite Element ◽  
Room Temperature ◽  
Proximity Effects ◽  
Rapidly Solidify ◽  
Process Step ◽  
Spatial Gradients ◽  
Adjacent Structures ◽  
Single Process ◽  
Single Process Step

AbstractWe investigate a method for non-contact patterning of molten polymer nanofilms based on thermocapillary modulation. Imposed thermal distributions along the surface of the film generate spatial gradients in surface tension. The resulting interfacial stresses are used to shape and mold nanofilms into 3D structures, which rapidly solidify when cooled to room temperature. Finite element simulations of the evolution of molten shapes illustrate how this technique can be used to fabricate features of different heights and separation distances in a single process step. These results provide useful guidelines for controlling proximity effects during evolution of adjacent structures.

Study of the morphological evolution of vanadium pentoxide nanostructures under hydrothermal conditions

CrystEngComm ◽  
2016 ◽  
Vol 18 (39) ◽  
pp. 7636-7641 ◽  
Author(s):  
W. Avansi ◽  
C. L. P. Oliveira ◽  
C. Ribeiro ◽  
E. R. Leite ◽  
V. R. Mastelaro
Keyword(s):  
Vanadium Pentoxide ◽  
Morphological Evolution ◽  
Hydrothermal Conditions

scholarly journals Ocean resurge-induced impact melt dynamics on the peak-ring of the Chicxulub impact structure, Mexico

2021 ◽  
Author(s):  
Felix M. Schulte ◽  
◽  
Axel Wittmann ◽  
Stefan Jung ◽  
Joanna V. Morgan ◽  
...  
Keyword(s):  
Impact Structure ◽  
Physical Processes ◽  
Hydrothermal Conditions ◽  
Chemical Examination ◽  
Impact Melt ◽  
Target Rock ◽  
Single Process ◽  
Chicxulub Impact ◽  
The Impact

AbstractCore from Hole M0077 from IODP/ICDP Expedition 364 provides unprecedented evidence for the physical processes in effect during the interaction of impact melt with rock-debris-laden seawater, following a large meteorite impact into waters of the Yucatán shelf. Evidence for this interaction is based on petrographic, microstructural and chemical examination of the 46.37-m-thick impact melt rock sequence, which overlies shocked granitoid target rock of the peak ring of the Chicxulub impact structure. The melt rock sequence consists of two visually distinct phases, one is black and the other is green in colour. The black phase is aphanitic and trachyandesitic in composition and similar to melt rock from other sites within the impact structure. The green phase consists chiefly of clay minerals and sparitic calcite, which likely formed from a solidified water–rock debris mixture under hydrothermal conditions. We suggest that the layering and internal structure of the melt rock sequence resulted from a single process, i.e., violent contact of initially superheated silicate impact melt with the ocean resurge-induced water–rock mixture overriding the impact melt. Differences in density, temperature, viscosity, and velocity of this mixture and impact melt triggered Kelvin–Helmholtz and Rayleigh–Taylor instabilities at their phase boundary. As a consequence, shearing at the boundary perturbed and, thus, mingled both immiscible phases, and was accompanied by phreatomagmatic processes. These processes led to the brecciation at the top of the impact melt rock sequence. Quenching of this breccia by the seawater prevented reworking of the solidified breccia layers upon subsequent deposition of suevite. Solid-state deformation, notably in the uppermost brecciated impact melt rock layers, attests to long-term gravitational settling of the peak ring.

Coarsening Kinetics and Morphological Evolution in a Two-Phase Titanium Alloy During Heat Treatment

2016 ◽  
Vol 25 (3) ◽  
pp. 734-743 ◽  
Author(s):  
Jianwei Xu ◽  
Weidong Zeng ◽  
Zhiqiang Jia ◽  
Xin Sun ◽  
Yawei Zhao
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
Morphological Evolution ◽  
Two Phase ◽  
Coarsening Kinetics

Thermal Processing of Polycrystalline NiTi Shape Memory Alloys

2004 ◽  
Vol 855 ◽  
Author(s):  
Carl P. Frick ◽  
Alicia M. Ortega ◽  
Jeff Tyber ◽  
Ken Gall ◽  
Hans J. Maier ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Shape Memory ◽  
Hot Rolling ◽  
Rolling Process ◽  
Heat Treatments ◽  
Treatment Temperature ◽  
Precipitate Size ◽  
Stress Strain ◽  
Transformation Temperatures ◽  
Strain Behavior

ABSTRACTThe objective of this study is to examine the effect of heat treatment on polycrystalline Ti-50.9 at.%Ni subsequent to hot-rolling. In particular we examine microstructure, transformation temperatures and mechanical behavior of deformation processed NiTi. The results constitute a fundamental understanding of the effect of heat treatment on thermal/stress induced martensite, which is critical for optimizing mechanical properties. The high temperature of the hot-rolling process caused recrystallization, recovery, and hindered precipitate formation, essentially solutionizing the NiTi. Subsequent heat treatments were carried out at various temperatures for 1.5 hours. Transmission Electron Microscopy (TEM) observations revealed that Ti3Ni4 precipitates progressively increased in size and changed their interface with the matrix from being coherent to incoherent with increasing heat treatment temperature. Accompanying the changes in precipitate size and interface coherency, transformation temperatures were observed to systematically shift, leading to the occurrence of the R-phase and multiple-stage transformations. Room temperature stress-strain tests illustrated a variety of mechanical responses for the various heat treatments, from pseudoelasticity to shape memory. The changes in stress-strain behavior are interpreted in terms of shifts in the primary martensite transformation temperatures, rather then the occurrence of the R-phase transformation. The results confirm that Ti3Ni4 precipitates can be used to elicit a desired isothermal stress-strain behavior in polycrystalline NiTi.

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