A TEM study of the interface between organic matrix and aragonite in a biological hard tissue, nacre

1992 ◽  
Vol 50 (2) ◽  
pp. 1024-1025
Author(s):  
Jun Liu ◽  
Katie E. Gunnison ◽  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Mechanical Properties ◽  
Ion Beam ◽  
Laminated Composite ◽  
Organic Matrix ◽  
Pearl Oyster ◽  
Interfacial Structure ◽  
Interfacial Region ◽  
Thin Sections ◽  
Organic Layers ◽  
Transmission Electron

The interfacial structure between the organic and inorganic phases in biological hard tissues plays an important role in controlling the growth and the mechanical properties of these materials. The objective of this work was to investigate these interfaces in nacre by transmission electron microscopy. The nacreous section of several different seashells -- abalone, pearl oyster, and nautilus -- were studied. Nacre is a laminated composite material consisting of CaCO3 platelets (constituting > 90 vol.% of the overall composite) separated by a thin organic matrix. Nacre is of interest to biomimetics because of its highly ordered structure and a good combination of mechanical properties. In this study, electron transparent thin sections were prepared by a low-temperature ion-beam milling procedure and by ultramicrotomy. To reveal structures in the organic layers as well as in the interfacial region, samples were further subjected to chemical fixation and labeling, or chemical etching. All experiments were performed with a Philips 430T TEM/STEM at 300 keV with a liquid Nitrogen sample holder.

Metallic Nanoneedles Arrays for TEM Sample Preparation “Lift-Out”

2012 ◽  
Author(s):  
Romaneh Jalilian ◽  
David Mudd ◽  
Neil Torrez ◽  
Jose Rivera ◽  
Mehdi M. Yazdanpanah ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Sample Preparation ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam System ◽  
Transmission Electron ◽  
Nanoneedle Array ◽  
Superior Mechanical Properties ◽  
And Performance

Abstract The sample preparation for transmission electron microscope can be done using a method known as "lift-out". This paper demonstrates a method of using a silver-gallium nanoneedle array for a quicker sharpening process of tungsten probes with better sample viewing, covering the fabrication steps and performance of needle-tipped probes for lift-out process. First, an array of high aspect ratio silver-gallium nanoneedles was fabricated and coated to improve their conductivity and strength. Then, the nanoneedles were welded to a regular tungsten probe in the focused ion beam system at the desired angle, and used as a sharp probe for lift-out. The paper demonstrates the superior mechanical properties of crystalline silver-gallium metallic nanoneedles. Finally, a weldless lift-out process is described whereby a nano-fork gripper was fabricated by attaching two nanoneedles to a tungsten probe.

Characterization of size, aspect ratio and degree of dispersion of particles in filled polymeric composites using FIB

Clay Minerals ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 195-205 ◽  
Author(s):  
Y. Zhu ◽  
G. C. Allen ◽  
J. M. Adams ◽  
D. Gittins ◽  
P. J. Heard ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Polymeric Composites ◽  
Degree Of Dispersion ◽  
Transmission Electron ◽  
Twin Screw ◽  
Mineral Fillers

AbstractTwo types of mineral fillers, talc and mica, were compounded into polypropylene (PP) via a twin-screw extruder. The morphologies and mechanical properties of the resultant composites were investigated. The dispersion of minerals in PP was observed using Focused Ion Beam (FIB) techniques. The particle size distribution (PSD) and aspect ratio (AR) of particles in the polymer phase were obtained from FIB image analysis. It was found that FIB imaging displays directly the micron to mesoscale level dispersion of particles in polymeric composites. The technique has significant potential for characterizing such materials, having some advantages over ‘traditional’ scanning and transmission electron microscopy in terms of generating representative data in a realistic timescale. The PSD and AR distribution and degree of dispersion in the composites give insights into the modification of mechanical properties of the composites studied.

Matrix-Mediated Biomineralization in Marine Mollusks: A Combined Transmission Electron Microscopy and Focused Ion Beam Approach

2011 ◽  
Vol 17 (2) ◽  
pp. 220-225 ◽  
Author(s):  
Martin Saunders ◽  
Charlie Kong ◽  
Jeremy A. Shaw ◽  
Peta L. Clode
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
High Strength ◽  
Organic Matrix ◽  
Dark Field ◽  
Transmission Electron ◽  
Annular Dark Field ◽  
The Relationship

AbstractThe teeth of the marine mollusk Acanthopleura hirtosa are an excellent example of a complex, organic, matrix-mediated biomineral, with the fully mineralized teeth comprising layers of iron oxide and iron oxyhydroxide minerals around a calcium apatite core. To investigate the relationship between the various mineral layers and the organic matrix fibers on which they grew, sections have been prepared from specific features in the teeth at controlled orientations using focused ion beam processing. Compositional and microstructural details of heterophase interfaces, and the fate of the organic matrix fibers within the mineral layers, can then be analyzed by a range of transmission electron microscopy (TEM) techniques. Energy-filtered TEM highlights the interlocking nature of the various mineral phases, while high-angle annular dark-field scanning TEM imaging demonstrates that the organic matrix continues to exist in the fully mineralized teeth. These new insights into the structure of this complex biomaterial are an important step in understanding the relationship between its structural and physical properties and may help explain its high strength and crack-resistance behavior.

Structure-Mechanical Property Relationships In A Biological Ceramic-Polymer Composite: Nacre

1991 ◽  
Vol 255 ◽  
Author(s):  
Katie E. Gunnison ◽  
Mehmet Sarikaya ◽  
Jun Liu ◽  
Ilhan A. Aksay
Keyword(s):  
Mechanical Property ◽  
Bending Strength ◽  
Organic Matrix ◽  
High Energy ◽  
Primary Component ◽  
Interfacial Structure ◽  
Interfacial Region ◽  
Toughening Mechanisms ◽  
Brick And Mortar ◽  
High Energy Absorption

AbstractThe structure-mechanical property relationships were studied in nacre, a laminated ceramicpolymer biocomposite found in seashell. Four-point bending strength and three-point bend fracture toughness tests were performed, and the results averaged 180 ± 30 MPa and 9 ± 3 MPa·m1/2, respectively, indicating that the composite is many orders of magnitude stronger and tougher than monolithic CaCO3,, which is the primary component of nacre. Fractographic studies conducted with a scanning electron microscope identified two significant toughening mechanisms in the well-known “brick and mortar” microstructure of nacre: (i) sliding of the aragonite platelets and (ii) ligament formation in the organic matrix. These toughening mechanisms allow for high energy absorption and damage tolerance and thereby prevent catastrophic failure of the composite. The structure of the organic matrix and the interfacial structure between the organic and inorganic components were studied with transmission electron microscopy by using both ion milled and ultramicrotomed sections with and without the intact aragonite platelets. We found that the organic matrix is indeed a multilayered composite at the nanometer scale but is thinner (about 100 Å) than reported in the literature. The morphology of the interfacial region between the organic and the inorganic layers suggests the presence of a structural “transitory” region that interlocks the two dissimilar phases.

scholarly journals Krypton and Helium Irradiation Damage in Yttria-stabilised Zirconia

2011 ◽  
Vol 1298 ◽  
Author(s):  
M. Gilbert ◽  
C. Davoisne ◽  
M. C. Stennett ◽  
N. C. Hyatt ◽  
N. Peng ◽  
...  
Keyword(s):  
Ion Beam ◽  
Cluster Formation ◽  
Matrix Material ◽  
Alpha Decay ◽  
Irradiation Damage ◽  
Thin Sections ◽  
Inert Matrix ◽  
Atomic Displacements ◽  
Transmission Electron ◽  
Focussed Ion Beam

ABSTRACTA candidate matrix material for inert matrix fuel (IMF), yttria-stabilised zirconia (YSZ) has been doped with Nd3+ as a surrogate for Pu3+. To simulate and assess the effects of fission gas accommodation and alpha decay on the microstructure, samples of (Y0.1425,Nd0.05,Zr0.8075)O1.904 have been irradiated with 2 MeV 36Kr+ ions, at fluences of 1×1014 and 5×1015 cm−2, and 200 keV 4He+ ions at fluences of 1×1014, 5×1015 and 1×1017 cm-2. Analysis by transmission electron microscopy (TEM) of thin sections prepared by focussed ion beam (FIB) milling revealed damage was only observed at the highest 36Kr+ and 4He+ fluences. Monte Carlo simulations using the TRIM code showed that it is only at these fluences that the level of atomic displacements was sufficient to result in observable defect cluster formation within the material.

State of Dispersion of Reinforcing Silica in a Silicone Elastomer, as Investigated by Transmission Electron Microscopy

2000 ◽  
Vol 661 ◽  
Author(s):  
Rex J Field ◽  
Jeanne Cambray ◽  
Joachim Floess ◽  
Stephane Rouanet
Keyword(s):  
Mechanical Properties ◽  
Fumed Silica ◽  
The State ◽  
Submicron Particles ◽  
High Porosity ◽  
Thin Sections ◽  
Visual Appearance ◽  
Commercial Success ◽  
Transmission Electron ◽  
Silicone Rubbers

ABSTRACTCommercial silicone rubbers typically contain submicron particles dispersed within them, the particles being responsible for the mechanical properties required for commercial success. Fumed silica has long been used for the reinforcement of higher-perfomance silicone rubber compositions, but high-porosity aerogels can function as well. The object of the work here was to compare the state of dispersion of some high-porosity aerogels with that of a fumed silica.Model silicone HCR (“heat-cured rubber”) compositions were prepared, and their mechanical properties characterized. Thin sections of the rubbers were then examined by TEM.Much of the fumed silica had been dispersed to give sub-micron sized features, although a number of larger features were present. The hydrophobic aerogel, in contrast, had been dispersed to give even finer features in the rubber, with very few super-micron fragments. The state of dispersion of the hydrophilic aerogel was quite different, showing many poorly-broken down large fragments up to 5 µm or more in diameter. The visual appearance of the compound reflected this poorer state of dispersion.

Using the Focused Ion Beam to Perform Serial Sectioning of Micron-Sized Particles for Coordinated Nanoscale Analysis

2008 ◽  
Vol 1089 ◽  
Author(s):  
Nabil D. Bassim ◽  
Bradley T. De Gregorio ◽  
Rhonda M. Stroud
Keyword(s):  
Focused Ion Beam ◽  
Electronic Device ◽  
Ion Beam ◽  
Forensic Analysis ◽  
Dust Particles ◽  
Serial Sectioning ◽  
Tem Analysis ◽  
Thin Sections ◽  
Transmission Electron ◽  
Section Form

AbstractStandard Focused Ion Beam (FIB) lift-out methods for production of transmission electron microscopy (TEM) thin sections destroy many cubic microns of material in order to produce a single 100-nm thick section. Microtome sectioning, in contrast, allows serial sectioning of adjacent multiple 100-nm sections, without loss of materials between sections, but lacks site specificity. In order to maximize the yield of analyzable material in thin section form from valuableone-of-a kind- micron-sized samples, we have developed serial sectioning techniques that combine FIB lift-out with microtomy. In this paper, we show an example of sectioning and subsequent TEM analysis of simulated cometary residues which resemble impact craters collected during the NASA Stardust Mission. These techniques may be generalized to any one-of-a-kind sample for which preserving analyzable volume is critical, such as forensic analysis of dust particles, failure analysis and electronic device sectioning.

Microstructure and Local Mechanical Properties of Skutterudites with Addition of Metallic Borides

2018 ◽  
Vol 784 ◽  
pp. 9-14
Author(s):  
Jiří Buršík ◽  
Vilma Buršíková ◽  
Gerda Rogl ◽  
Peter Rogl
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Figure Of Merit ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Analytical Transmission Electron Microscopy ◽  
Important Class ◽  
Transmission Electron ◽  
P Type ◽  
Dynamic Nanoindentation

Skutterudites are an important class of thermoelectric p- and n-type materials and they have already achieved fair efficiencies for the conversion of heat to electricity. Nevertheless researchers try to further enhance the figure of merit, ZT, by various ways. In this work we study microstructure and mechanical properties of two thermoelectric materials: an industrial n-type (Mm,Sm)yCo4Sb12 skutterudite and an industrial p-type DDyFe3CoSb12 skutterudite, both mixed with 1 wt.% of Ta0.8Zr0.2B. Thin lamellae were prepared from the compacted materials using a focused ion beam. Analytical transmission electron microscopy was used on lamellae to study details of microstructure. A fine dispersion of precipitates was found both at nanograin boundaries and in their interiors. Quasistatic and dynamic nanoindentation tests were carried out on planar polished sections in the range of applied loads from 0.01 to 10 mN. The results were complemented with quantitative modulus mapping of local mechanical properties with 10-nm resolution.

Microstructure and Mechanical Properties of Nanolayered TiN/Cu Thin Films

2003 ◽  
Vol 778 ◽  
Author(s):  
Y.Y. Tse ◽  
G. Abadias ◽  
A. Michel ◽  
C. Tromas ◽  
M. Jaouen
Keyword(s):  
Mechanical Properties ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
X Ray Diffraction ◽  
Depth Sensing ◽  
Transmission Electron ◽  
Beam Sputtering ◽  
Hardness Increase ◽  
Dual Ion Beam Sputtering ◽  
The Relationship

AbstractStructural and mechanical properties of nanoscale TiN/Cu multilayers grown by dual ion beam sputtering with bilayer periods (A) ranging from 2.5 to 50 nm were studied. Both low-angle and high-angle X-ray diffraction (XRD) experiments have been employed to globally characterize the multilayers structure. The microstructure of the multilayers has been scrutinized by high resolution transmission electron microscopy (HRTEM). The effects of interface and bilayer thickness on hardness were investigated by depth-sensing nanoindentation technique. A small hardness increase with decreasing periodicity of the multilayers has been observed. The relationship between the hc/T ratio (hc is the contact depth and T is the total film thickness) and the hardness is established. The correlation between the microstructure and hardness is discussed.

Microstructure of the avian eggshell

1993 ◽  
Vol 51 ◽  
pp. 170-171
Author(s):  
S.Q. Xiao ◽  
M. Agarwal ◽  
A.H. Heuer
Keyword(s):  
Cross Section ◽  
Ion Beam ◽  
Outer Part ◽  
Organic Matrix ◽  
Collagen Fibers ◽  
Palisade Layer ◽  
Thin Sections ◽  
Shell Membrane ◽  
Sem Study ◽  
Fine Organic

Fresh white and dry brown eggshells were studied by TEM and SEM. For TEM, thin sections of the eggshell were prepared by both ultramicrotomy and ion-beam thinning.The various regions from the inner to the outer part of the eggshell can be summarized as follows : the shell membrane, the mammillary layer, the palisade layer and the cuticle. The shell membrane is about 80 μm thick and is composed of collagen fibers with a mantle and core structure. The mammillary layer is a mixture of calcite crystallites, organic matrix and collagen fibers; it starts at the outer shell membrane and merges gradually into the palisade layer. The collagen fibers present near the palisade are surrounded by tiny calcite crystals (Fig. 1). In this region, the periphery of fibers are calcified. The SEM study of the etched cross section revealed clusters of fine organic sheets at the junction of the membrane and the palisade layer (Fig. 2). Further etching results in the collapse of these sheets, to form knob-like features on the surface of the membrane.

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