Atomic structure determination of NIO-ZRO2(CaO) and NI-ZRO2(CaO) interfaces using Z-contrast imaging and EELS

1996 ◽  
Vol 54 ◽  
pp. 106-107
Author(s):  
E.C. Dickey ◽  
V.P. Dravid ◽  
P. Nellist ◽  
D.J. Wallis ◽  
N. D. Browning ◽  
...  
Keyword(s):  
Atomic Structure ◽  
Bulk Material ◽  
Interface Structure ◽  
Structure Property ◽  
Contrast Imaging ◽  
Spatially Resolved ◽  
Structure Property Relationships ◽  
Powerful Approach ◽  
Resolution Imaging ◽  
Z Contrast

Combining atomic-resolution imaging with spatially resolved electron energy loss spectroscopy (EELS) is a powerful approach to probing the geometric, chemical and electronic aspects of internal interfaces. By elucidating these interrelated constituents of interface structure, one can begin to understand the influence of the interface atomic structure on relevant bulk material properties, deducing atomic structure/property relationships. The combined Z-contrast and EELS approach was applied to two types of heterophase interfaces: oxide-oxide (NiO-ZrO2) and metal-oxide (Ni-ZrO2). The interface structure will be discussed in light of these experiments and compared to previous HREM results.

Atomic Scale Analysis of a YSZ Bicrystal Grain Boundary

2001 ◽  
Vol 7 (S2) ◽  
pp. 400-401
Author(s):  
Y. Lei ◽  
Y. Ito ◽  
N. D. Browning
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Bulk Material ◽  
Atomic Scale ◽  
Structure Property ◽  
Contrast Imaging ◽  
Structure Property Relationships ◽  
Commercial Applications ◽  
Z Contrast ◽  
Electron Energy Loss

Yttria-stabilized zirconia (YSZ) has been the subject of many experimental and theoretical studies, due to the commercial applications of zirconia-based ceramics in solid state oxide fuel cells. Since the grain boundaries usually dominate the overall macroscopic performance of the bulk material, it is essential to develop a fundamental understanding of their structure-property relationships. Previous research has been performed on the atomic structure of grain boundaries in YSZ, but no precise atomic scale compositional and chemistry characterization has been carried out. Here we report a detailed analytical study of an [001] symmetric 24° bicrystal tilt grain boundary in YSZ prepared with ∼10 mol % Y2O3 by Shinkosha Co., Ltd by the combination of Z-contrast imaging and electron energy loss spectroscopy (EELS).The experimental analysis of the YSZ sample was carried out on a 200kV Schottky field emission JEOL 201 OF STEM/TEM4.

Z-contrast imaging of an ordered interface structure in the Si/CoSi2/Si system

1993 ◽  
Vol 51 ◽  
pp. 802-803
Author(s):  
M. F. Chisholm ◽  
D. E. Jesson ◽  
S. J. Pennycook ◽  
S. Mantl
Keyword(s):  
Atomic Structure ◽  
Substrate Surface ◽  
Interface Structure ◽  
Unit Cell ◽  
Contrast Imaging ◽  
Treatment Results ◽  
Semiconductor Interfaces ◽  
Contrast Technique ◽  
Z Contrast ◽  
Insight Into

We show the atomic structure of buried CoSi2/Si(001) boundaries involves a 2×1 ordering of the interfacial Co atoms. The ability to directly image and interpret this unforeseen structure is possible through the Z-contrast technique, and presents a new level of insight into the important and controversial relationship between the atomic structure and electronic properties, such as the energy barrier for electron transport across metal-semiconductor interfaces.The buried CoSi2 layer was produced by implanting Co+ ions (200 keV, 2 × 1017 ions/cm2) in a Si(001) substrate heated to 350°C. The substrate was capped with 200 nm of SiO2 and then given a two-step anneal in high purity argon (750°C for 30 s + 1150°C for 10 s). This treatment results in a continuous buried CoSi2 layer ~70 nm thick, ~90 nm below the substrate surface. The layer and the substrate are oriented such that the cubic CaF2 unit cell of CoSi2 is aligned parallel to the cubic unit cell of Si.

A Combined-Techniques Approach to Elucidating Crystalline Interface Atomic Structure

1996 ◽  
Vol 466 ◽  
Author(s):  
E. C. Dickey ◽  
V. P. Dra Vid ◽  
S. J. Pennycook ◽  
P. D. Nellist ◽  
D. J. Wallis
Keyword(s):  
Atomic Structure ◽  
Three Dimensional ◽  
Interface Structure ◽  
Contrast Imaging ◽  
Imaging And Spectroscopy ◽  
Complementary Techniques ◽  
Electron Imaging ◽  
Z Contrast ◽  
Interface Structures

ABSTRACTA case study is presented in which HREM, Z-Contrast Imaging and EELS are used as complementary techniques for elucidating interface structure. The NiO-ZrO2(cubic) interface is investigated along two orthogonal directions by these electron imaging and spectroscopy techniques to reveal the three-dimensional interface structure. Based on findings from this study, a protocol is suggested for using all three experimental techniques to gain a thorough understanding of interface structures.

Investigating Atomic Scale Structure-property Relationships at Grain Boundaries

1998 ◽  
Vol 4 (S2) ◽  
pp. 790-791
Author(s):  
N. D. Browning ◽  
H. O. Moltaji ◽  
E. M. James ◽  
S. Stemmer ◽  
J. P. Buban ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Grain Boundaries ◽  
Atomic Scale ◽  
Structure Property ◽  
Contrast Imaging ◽  
Structure Property Relationships ◽  
Unique Interpretation ◽  
Conventional Structure ◽  
Compositional Changes ◽  
Z Contrast

Although grain boundaries are known to dominate the bulk properties of many technologically important materials, in most cases there is no fundamental atomic scale understanding of why they should have such an effect. One of the problems in developing this understanding is that conventional structure determination techniques, such as phase contrast imaging in TEM or Z-contrast imaging in STEM, produce only a 2-dimensional projection of the crystal structure. Atomic scale compositional changes must be simulated and a unique interpretation is clouded by boundary reconstructions and strain effects. Furthermore, neither technique provides any information on the local changes in the electronic structure that are critical for both the electrical and mechanical properties of the boundary.EELS provides a means to quantify local changes in both composition and electronic structure. However, without a knowledge of the structure, interpretation of any observed changes at grain boundaries is extremely difficult.

scholarly journals Nanoscale bubble domains with polar topologies in bulk ferroelectrics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jie Yin ◽  
Hongxiang Zong ◽  
Hong Tao ◽  
Xuefei Tao ◽  
Haijun Wu ◽  
...  
Keyword(s):  
Physical Properties ◽  
Bulk Material ◽  
Condensed Matter ◽  
Time Dependent ◽  
Morphology Evolution ◽  
Contrast Imaging ◽  
Ferroelectric Films ◽  
Modulated Phases ◽  
Ferroelectric Memories ◽  
Z Contrast

AbstractMultitudinous topological configurations spawn oases of many physical properties and phenomena in condensed-matter physics. Nano-sized ferroelectric bubble domains with various polar topologies (e.g., vortices, skyrmions) achieved in ferroelectric films present great potential for valuable physical properties. However, experimentally manipulating bubble domains has remained elusive especially in the bulk form. Here, in any bulk material, we achieve self-confined bubble domains with multiple polar topologies in bulk Bi0.5Na0.5TiO3 ferroelectrics, especially skyrmions, as validated by direct Z-contrast imaging. This phenomenon is driven by the interplay of bulk, elastic and electrostatic energies of coexisting modulated phases with strong and weak spontaneous polarizations. We demonstrate reversable and tip-voltage magnitude/time-dependent donut-like domain morphology evolution towards continuously and reversibly modulated high-density nonvolatile ferroelectric memories.

Investigating Ca Segregated to a Grain Boundaries in MgO Using Multiple Scattering Analysis of Electron Energy Loss Spectra

1998 ◽  
Vol 4 (S2) ◽  
pp. 776-777
Author(s):  
J. P. Buban ◽  
J. Zaborac ◽  
H. Moltaji ◽  
G. Duscher ◽  
N. D. Browning
Keyword(s):  
Energy Loss ◽  
Grain Boundaries ◽  
Electron Energy ◽  
Structural Model ◽  
Boundary Structure ◽  
Structure Property ◽  
Contrast Imaging ◽  
Scale Properties ◽  
Z Contrast ◽  
Electron Energy Loss

Although grain boundaries typically account for only a small fraction of a material, they can have far reaching effects on the overall bulk scale properties. These effects are usually simply linked to the boundary having a different atomic arrangement to the bulk. A necessary first step in understanding the structure-property relationships is therefore a detailed determination of the boundary structure.One means of obtaining detailed information on the structure of grain boundaries is through correlated Z-contrast imaging and electron energy loss spectroscopy (EELS). The Z-contrast image generates a map of the grain boundary which can be used to position the probe in defined locations for spectroscopy. In the case of oxides, a structural model of the metal atom positions can be determined directly from the image. Furthermore, using a simple bond-valence sum minimization routine, the oxygen atoms can be placed so that the structure contains atoms that have valences consistent with their expected formal valence state.

In situ characterization of Cu–Co oxides for catalytic application

2015 ◽  
Vol 177 ◽  
pp. 249-262 ◽  
Author(s):  
Z. Y. Tian ◽  
H. Vieker ◽  
P. Mountapmbeme Kouotou ◽  
A. Beyer
Keyword(s):  
Thermal Properties ◽  
Chemical Vapor ◽  
Functional Materials ◽  
Catalytic Performance ◽  
Structure Property ◽  
Temperature Oxidation ◽  
Spatially Resolved ◽  
Structure Property Relationships ◽  
Potential Applications

In situ emission and absorption FTIR methods were employed to characterize the spatially resolved structure of binary Co–Cu oxides for low-temperature oxidation of CO and propene. Co–Cu oxide catalysts were controllably synthesized by pulsed-spray evaporation chemical vapor deposition. XRD, FTIR, XPS, UV-vis and helium ion microscopy (HIM) were employed to characterize the as-prepared thin films in terms of structure, composition, optical and thermal properties as well as morphology. In situ emission FTIR spectroscopy indicates that Co3O4, CuCo2O4 and CuO are thermally stable at 650, 655 and 450 °C, respectively. The catalytic tests with absorption FTIR display that the involvement of Co–Cu oxides can initiate CO and C3H6 oxidation at lower temperatures. The results indicate that in situ emission and absorption FTIR are useful techniques to explore the thermal properties and catalytic performance of functional materials, allowing many potential applications in tailoring their temporally and spatially resolved structure-property relationships.

Atomic Structure of Interfaces in Epitaxial NiSi2 on (001) Silicon

1992 ◽  
Vol 263 ◽  
Author(s):  
W.J. Chen ◽  
F.R. Chen ◽  
L.J. Chen
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Atomic Structure ◽  
Imaging Technique ◽  
Interface Structure ◽  
High Resolution Imaging ◽  
Image Simulation ◽  
Transmission Electron ◽  
Resolution Imaging ◽  
Boundary Core

ABSTRACTHigh resolution transmission electron microscopy (HRTEM) has been applied to study the atomic structure of NiSi2 /(001)Si interface. Previous HRTEM result suggested that Ni atoms in the boundary core are six-fold coordinated and Si atoms are everywhere tetrahedrally coordinated. In this work, high resolution imaging technique and computer image simulation were used to study the atomic structure of NiSi2 /(001)Si interfaces and a new interface structure was found. For the new interface structure, Ni and Si atoms are also six-fold and tetrahedrally coordinated, respectively, with an extra layer of fourfold planar bonded Si atoms present at the interface.

Z-Contrast Imaging of Heavy Metal Particles Supported in A Zeolitic Matrix Via High-Resolution Stem

1987 ◽  
Vol 45 ◽  
pp. 204-205
Author(s):  
J. H. Butler ◽  
G. M. Brown
Keyword(s):  
High Resolution ◽  
Incident Beam ◽  
Dark Field ◽  
Irradiation Damage ◽  
Contrast Imaging ◽  
Vacuum Oven ◽  
Annular Dark Field ◽  
Resolution Imaging ◽  
Beam Currents ◽  
Z Contrast

High resolution Imaging of zeolites is difficult because these materials are very susceptible to Irradiation damage. It is now well known that dehydrated samples are more stable under the electron beam. Thus the most successful high resolution studies of zeolites to date have been on samples which were freeze-fractured and subsequently dehydrated via heating in a vacuum oven. Electron microscopy was then performed using a combination of low Incident beam currents and sensitive detectors. One problem with this method is that zeolites fracture along cleavage planes and therefore are deposited on microscope grids In a particular orientation. This limits the range of viewing angles. Here we describe a method of sample preparation via ultramlctrotomy as well as the establishment of suitable FEG/STEM Imaging conditions which permit the observation of small (7-14 A diameter) Pt particles within Individual zeolite channels using the method of Z-contrast as applied with a high-angle annular dark field detector. This method allows observation over all crystalline orientations for relatively long exposures to the beam.

scholarly journals Atomic Scale Structure and Chemistry of Interfaces by Z-Contrast Imaging and Electron Energy Loss Spectroscopy in the Stem

1993 ◽  
Vol 319 ◽  
Author(s):  
M.M. Mcgibbon ◽  
N.D. Browning ◽  
M.F. Chisholm ◽  
S.J. Pennycook ◽  
V. Ravikumar ◽  
...  
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Structural Information ◽  
Atomic Scale ◽  
Boundary Structure ◽  
Structure Property ◽  
Contrast Imaging ◽  
Z Contrast ◽  
Electron Energy Loss

AbstractThe macroscopic properties of many materials are controlled by the structure and chemistry at grain boundaries. A basic understanding of the structure-property relationship requires a technique which probes both composition and chemical bonding on an atomic scale. The high-resolution Z-contrast imaging technique in the scanning transmission electron microscope (STEM) forms an incoherent image in which changes in atomic structure and composition can be interpreted intuitively. This direct image allows the electron probe to be positioned over individual atomic columns for parallel detection electron energy loss spectroscopy (EELS) at a spatial resolution approaching 0.22nm. In this paper we have combined the structural information available in the Z-contrast images with the bonding information obtained from the fine structure within the EELS edges to determine the grain boundary structure in a SrTiO3 bicrystal.

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