Formation of Pb Inclusions in Si by Ion Implantation

1997 ◽  
Vol 504 ◽  
Author(s):  
V. S. Touboltsev ◽  
E. Johnson ◽  
U. Dahmen ◽  
A. Johansen ◽  
L. Sarholt ◽  
...  

AbstracrSi<110> single crystals were implanted at a temperature of 835 K with 150 keV Pb+ ions to a fluence of 1·1020 m−2 corresponding to an average concentration of 2–3 at%. The implanted samples have been studied by Rutherford Backscattering (RBS)/channeling and transmission electron microscopy (TEM) techniques. In as-implanted samples the main fraction of implanted Pb was located on substitutional sites in the Si matrix thus providing a highly supersaturated solution of Pb in Si. Spontaneous precipitation of Pb, giving rise to formation of nanosized Pb inclusions, was found to take place only in the peak region of the implantation. TEM analysis showed that the Pb precipitates had sizes from about 2 to 20 nm and that they grew in parallel cube orientation relationship with the host matrix. The shape of the inclusions was found to be approximately cuboctahedral with poorly developed {111} and {100} facets.In-situ RBS/channeling heating/cooling experiments on both as-implanted samples and samples previously furnace-annealed at 1175 K showed a distinct melting/solidification hysteresis of the Pb inclusions around the bulk melting point for Pb at 600 K. These results were verified by in-situ TEM heating/cooling experiments on as-implanted samples.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Karan Kumar Gupta ◽  
S . J. Dhoble ◽  
Aleksander R. Krupski

AbstractDy3+ doped β-Ca2P2O7 phosphor has been synthesized using wet chemical method. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis confirmed the formation of β-Ca2P2O7:Dy nano-phosphors. However, photoluminescence (PL) study was carried out to confirm the presence of dopant ion in the host matrix of β-Ca2P2O7:Dy material. Thermoluminescence (TL) glow curves of β-Ca2P2O7 were recorded for different concentrations of Dy3+ after exposure to various fluences of C6+ ion beam (75 meV). TL sensitivity of β-Ca2P2O7:Dy3+ (0.1 mol%) phosphor was 3.79 times more than commercially available CaSO4:Dy3+. TRIM code based on the Monte Carlo simulation was used to calculate the absorbed doses, ion range and main energy loss. Glow curve de-convolution (GCD) method was used to determine the number of TL peaks and their trapping parameters. The wide linear response of β-Ca2P2O7 nanoparticles along with high stability of TL glow curve makes this nanomaterial a good candidate for C6+ ion beam dosimetry.


MRS Advances ◽  
2016 ◽  
Vol 1 (42) ◽  
pp. 2893-2899 ◽  
Author(s):  
R.W. Harrison ◽  
H. Amari ◽  
G. Greaves ◽  
J.A. Hinks ◽  
S.E. Donnelly

AbstractIn-situ ion irradiation and transmission electron microscopy has been used to examine the effects of the He appm to DPA ratio, temperature and dose on the damage structure of tungsten (W). Irradiations were performed with 15 or 60 keV He+ ions, achieving He-appm/displacements per atom (DPA) ratios of ∼40,000 and ∼2000, respectively, at temperatures between 500 and 1000°C to a dose of ∼3 DPA. A high number of small dislocation loops with sizes around 5–20 nm and a He bubble lattice were observed for both He-appm/DPA ratios at 500°C with a bubble size ∼1.5 nm. Using the g.b=0 criterion the loops were characterised as b = ±1/2<111> type. At 750°C bubbles do not form an ordered array and are larger in size compared to the irradiations at 500°C, with a diameter of ∼3 nm. Fewer dislocation loops were observed at this temperature and were also characterised to be b = ±1/2<111> type. At 1000°C, no dislocation loops were observed and bubbles grew as a function of fluence attributed to vacancy mobility being higher and vacancy clusters becoming mobile.


Nanoscale ◽  
2019 ◽  
Vol 11 (21) ◽  
pp. 10486-10492 ◽  
Author(s):  
Fu-Chun Chen ◽  
Jui-Yuan Chen ◽  
Ya-Hsuan Lin ◽  
Ming-Yu Kuo ◽  
Yung-Jung Hsu ◽  
...  

The formation of different shapes Au–Cu2O core–shell nanoparticles was investigated by in situ liquid cell transmission electron microscopy (LCTEM).


CORROSION ◽  
10.5006/3457 ◽  
2020 ◽  
Vol 76 (5) ◽  
pp. 464-475 ◽  
Author(s):  
Shravan K. Kairy ◽  
Nick Birbilis

The role of magnesium silicide (Mg2Si) and silicon (Si) particles in the localized corrosion of aluminum (Al) alloys was investigated herein. Sub-micrometer-sized Mg2Si and Si particles were grown in the Al matrix of Al-Mg-Si and Al-Si alloys, respectively, and characterized by transmission electron microscopy (TEM). A quasi in situ TEM technique was used to study an identical location containing Mg2Si or Si particle in the Al matrix, prior to and following a period of immersion in 0.1 M NaCl at pH 6, 2, and 12. At pH 6 and 2, Mg2Si was initially “anodic,” preferentially dealloying via selective dissolution of Mg, resulting in the development of SiO-rich remnants that are electrochemically inert. The SiO-rich remnants at pH 2 physically detached from the Al matrix. Silicon particles were electrochemically inert at pH 6, while “cathodic” at pH 2, dissolving the Al matrix at their periphery. It was observed that copper (Cu) was redeposited on Si particles at pH 2. At pH 12, Mg2Si and Si were “cathodic” to the Al matrix. This study clarifies, and provides new insights into, the characteristics of Al alloy physical manifestation of corrosion associated with Mg2Si and Si at the nanoscale.


Parasitology ◽  
1993 ◽  
Vol 107 (5) ◽  
pp. 545-552 ◽  
Author(s):  
D. L. Lee ◽  
K. A. Wright ◽  
R. R. Shivers

SUMMARYThe surface of the cuticle of adult Nippostrongylus brasiliensis has been studied by means of the freeze-fracture technique and by transmission electron microscopy. Some of the surface coat appears to have been shed from the surface of the cuticle of adults fixed in situ in the intestine of its host and from the surface of individuals removed from the intestine and freeze-fractured. Freeze-fracturing the cuticle of individuals removed from the host has shown that this surface coat varies in thickness from 30 to 90 nm. The epicuticle is about 20 nm thick and cleaves readily to expose E- and P-faces. The P-face of the epicuticle possesses a small number of particles, similar to intra-membranous particles, whilst the E-face possesses a few, widely scattered depressions. Despite the presence of these particles the epicuticle is not considered to be a true membrane. Freeze-fracturing the remainder of the cuticle has confirmed its structure as described by conventional transmission electron microscopy. Clusters of particles on the P-face of the outer epidermal (hypodermal) membrane and corresponding depressions on the E-face of the membrane are thought to be associated with points of attachment of the cuticle to the epidermis (hypodermis). No differences in appearance of the cuticle and its surface layers were observed in individuals taken from 7-, 10-, 13- and 15-day infections.


2005 ◽  
Vol 907 ◽  
Author(s):  
Amanda K Petford-Long ◽  
Thomas Bromwich ◽  
Amit Kohn ◽  
Victoria Jackson ◽  
Takeshi Kasama ◽  
...  

AbstractOne of the most widely studied types of magnetic nanostructure is that used in devices based on the giant magnetoresistance (GMR) or tunnel magnetoresistance (TMR) phenomena. In order to understand the behaviour of these materials it is important to be able to follow their magnetisation reversal mechanism, and one of the techniques enabling micromagnetic studies at the sub-micron scale is transmission electron microscopy. Two techniques can be used: Lorentz transmission electron microscopy and off-axis electron holography, both of which allow the magnetic domain structure of a ferromagnetic material to be investigated dynamically in real-time with a resolution of a few nanometres. These techniques have been used in combination with in situ magnetizing experiments, to carry out qualitative and quantitative studies of magnetization reversal in a range of materials including spin-tunnel junctions, patterned thin film elements and magnetic antidot arrays. Quantitative analysis of the Lorentz TEM data has been carried out using the transport of intensity equation (TIE) approach.


2006 ◽  
Vol 05 (06) ◽  
pp. 951-958 ◽  
Author(s):  
XUEDONG BAI ◽  
EN GE WANG ◽  
ZHONG LIN WANG

Zinc oxide nanobelts, grown by a solid–vapor phase thermal sublimation process, are stimulating extensive interest because of their semiconducting and piezoelectric properties, diverse functionalities and chemical stability. For nanomanipulation and nanomeasurement of an individual ZnO nanobelts, in situ transmission electron microscopy (TEM) technique is a unique approach. In this paper, mechanical resonance of a single ZnO nanobelt, induced by an alternative electric field, was studied by in situ TEM. Due to the rectangular cross-section of the nanobelt, two fundamental resonance modes have been observed in corresponding to two orthogonal transverse vibration directions, showing the versatile applications of nanobelts as nanocantilevers and nanoresonators. The bending modulus of the ZnO nanobelts was measured to be ~ 52 GPa and the damping time constant of the resonance in vacuum of 10–8 Torr was ~ 1.2 ms. The ZnO nanobelts are promising in potential applications as nanocantilevers, nanoresonators and nanoactuators.


1997 ◽  
Vol 480 ◽  
Author(s):  
K. B. Belay ◽  
M. C. Ridgway ◽  
D. J. Llewellyn

AbstractIn-situ transmission electron microscopy (TEM) has been used to characterize the solidphase epitaxial growth of amorphized GaAs at a temperature of 260°C. To maximize heat transfer from the heated holder to the sample and minimize electron-irradiation induced artifacts, non-conventional methodologies were utilized for the preparation of cross-sectional samples. GaAs (3xI) mm rectangular slabs were cut then glued face-to-face to a size of (6x3) mm stack by maintaining the TEM region at the center. This stack was subsequently polished to a thickness of ~ 200 ýtm. A 3 mm disc was then cut from it using a Gatan ultrasonic cutter. The disc was polished and dimpled on both sides to a thickness of ~15 mimT.h is was ion-beam milled at liquid nitrogen temperature to an electron-transparent layer. From a comparison of in-situ and ex-situ measurements of the recrystallization rate, the actual sample temperature during in-situ characterization was estimated to deviate by ≤ 20°C from that of the heated holder. The influence of electron-irradiated was found to be negligible by comparing the recrystallization rate and microstructure of irradiated and unirradiated regions of comparable thickness. Similarly, the influence of “thin-foil effect” was found to be negligible by comparing the recrystallization rate and microstructure of thick and thin regions, the former determined after the removal of the sample from the microscope and further ion-beam milling of tens of microns of material. In conclusion, the potential influence of artifacts during in-situ TEM can be eliminated by the appropriate choice of sample preparation procedures.


Nanoscale ◽  
2017 ◽  
Vol 9 (35) ◽  
pp. 12835-12842 ◽  
Author(s):  
C. N. Shyam Kumar ◽  
Venkata Sai Kiran Chakravadhanula ◽  
Adnan Riaz ◽  
Simone Dehm ◽  
Di Wang ◽  
...  

In situ TEM analysis of the thermally induced graphitization and domain growth of free-standing nanocrystalline graphene thin films.


2014 ◽  
Vol 16 (34) ◽  
pp. 18176-18184 ◽  
Author(s):  
Farzad Behafarid ◽  
Sudeep Pandey ◽  
Rosa E. Diaz ◽  
Eric A. Stach ◽  
Beatriz Roldan Cuenya

The thermal and chemical stability of micelle-synthesized size-selected Pt nanoparticles (NPs) supported on thin SiO2(20 nm) films was monitoredin situ viatransmission electron microscopy (TEM) under pure hydrogen and pure oxygen environments.


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