In Situ High-Temperature Cross-Sectional TEM Specimen Preparation

1987 ◽  
Vol 115 ◽  
Author(s):  
Eric M. Fiore ◽  
Rodney A. Herring
Keyword(s):  
Phase Transformation ◽  
Electron Microscope ◽  
Thermal Processing ◽  
Defect Formation ◽  
High Energy ◽  
Formation Mechanisms ◽  
Specimen Preparation ◽  
Cross Sectional ◽  
Transmission Electron

ABSTRACTWe describe a technique for preparing transmission electron microscope (TEM) cross-sectional specimens for observation during in situ annealing to high temperatures. The process utilizes a ceramic adhesive that is stable to a temperature of 1650°C. The technique, which was successfully used to observe the recrystallization of amorphized silicon, is being applied to high-energy ion-implanted silicon in an attempt to better understand the amorphous-to-crystalline phase transformation and defect formation mechanisms resulting from thermal processing.

In Situ Analysis of magnetic and Structural Properties of Epitaxial and Polycrystalline Ni80Fe20 Thin Films

1993 ◽  
Vol 313 ◽  
Author(s):  
I. Hashim ◽  
H.A. Atwater ◽  
Thomas J. Watson
Keyword(s):  
Magnetic Properties ◽  
Kerr Effect ◽  
High Energy ◽  
Epitaxial Films ◽  
Interface Roughness ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Transmission Electron

ABSTRACTWe have investigated structural and magnetic properties of epitaxial Ni80Fe20 films grown on relaxed epitaxial Cu/Si (001) films. The crystallographic texture of these films was analyzed in situ by reflection high energy electron diffraction (RHEED), and ex situ by x-ray diffraction and cross-sectional transmission electron Microscopy (XTEM). In particular, RHEED intensities were recorded during epitaxial growth, and intensity profiles across Bragg rods were used to calculate the surface lattice constant, and hence, find the critical epitaxial thickness for which Ni80Fe20 grows pseudomorphically on Cu (100). XTEM analysis indicated that the epitaxial films had atomically-abrupt interfaces which was not the case for polycrystalline Cu and Ni80Fe20 film interfaces. The Magnetic properties of these epitaxial films were Measured in situ using Magneto-optic Kerr effect magnetometry and were compared with those of polycrystalline films grown on SiO2/Si. Large Hc (∼ 35 Oe) was observed for epitaxial Ni80Fe20 films less than 3.0 nm thick whereas for increasing thickness, Hc decreased approximately monotonically to a few Oersteds. Correlations were made between magnetic properties of these epitaxial films, the strain in the film and the interface roughness obtained from XTEM analysis.

Orientational and Microstructural Evolution During Epitaxial Growth of Cu on Si(001) by Sputter Deposition

1992 ◽  
Vol 280 ◽  
Author(s):  
I. Hashim ◽  
B. Park ◽  
H. A. Atwater
Keyword(s):  
Epitaxial Growth ◽  
Ion Beam ◽  
High Energy ◽  
Sputter Deposition ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Plan View ◽  
Transmission Electron

ABSTRACTEpitaxial Cu thin films have been grown on H-terminated Si(OOl) substrates at room temperature by D.C. ion-beam sputter deposition in ultrahigh vacuum. The development of orientation and microstructure during epitaxial growth from the initial stages of Cu growth up to Cu thicknesses of few hundred nm has been investigated. Analysis by in-situ reflection high energy electron diffraction, thin film x-ray diffraction, and plan-view and cross-sectional transmission electron microscopy indicates that the films are well textured with Cu(001)∥ Si(001) and Cu[100]∥ Si[110]. Interestingly, it is found that a distribution of orientations occurs at the early stages of Cu epitaxy on Si(001) surface, and that a (001) texture emerges gradually with increasing Cu thickness. The effect of silicide formation and deposition conditions on the crystalline quality of Cu epitaxy is also discussed.

Epitaxial Growth of Silicon on CoSi2 (001)/Si (001)

1991 ◽  
Vol 220 ◽  
Author(s):  
Q. F. Xiao ◽  
J. R. Jimenez ◽  
L. J. Schowalter ◽  
L. Luo ◽  
T. E. Mitchell ◽  
...  
Keyword(s):  
Growth Conditions ◽  
High Energy ◽  
Thin Layers ◽  
Ex Situ ◽  
High Crystalline Quality ◽  
Cross Sectional ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Reconstructed Surface

ABSTRACTEpitaxial Si layers have been grown under a variety of growth conditions on CoSi2 (001) by molecular beam epitaxy (MBE). The structural properties of the Si overgrowth were studied by in-situ Reflection High Energy Electron Diffraction (RHEED), as well as ex-situ MeV4He+ ion channeling and High Resolution Transmission Electron Microscopy (HRTEM). Strong influences of the CoSi2 surface reconstruction on the Si overgrowth have been observed. RHEED studies show islanding growth of Si on the CoSi2 (001) (3/√2 × √2)R45 reconstructed surface, but smooth growth of Si on the CoSi2 (001) {√2 × √2)R45 reconstructed surface, under the same growth conditions. The growth of Si on thin layers of CoSi2 (2nm-6nm) with (√2 × √2)R45 reconstructed surface at 460°C results in high crystalline quality for the Si top layer, as indicated by good channeling minimum yield (Xmin < 6%), but cross-sectional TEM shows that the CoSi2 layers are discontinuous. We also report preliminary results on Si grown on a 2 × 2 reconstructed CoSi2 (001) surface.

scholarly journals Trim Simulations and Possible Studies for Edge-on Ion Irradiation of Electron Microscope Specimens

1992 ◽  
Vol 279 ◽  
Author(s):  
Loren J. Thompson ◽  
Charles W. Allen ◽  
Marcus C. Frischherz ◽  
Mauro P. Otero
Keyword(s):  
Electron Microscope ◽  
Ion Irradiation ◽  
Special Technique ◽  
Specimen Preparation ◽  
Plan View ◽  
Depth Direction ◽  
Transmission Electron ◽  
Si Films ◽  
Foil Specimen

ABSTRACTA TRIM code [1] has been modified to simulate a special technique, first described at the Spring 92 MRS Meeting [2], for in situ transmission electron microscope (TEM) experiments involving simultaneous ion irradiation, in which the resultant phenomena are observed as in a cross-section TEM specimen without further specimen preparation. Instead of ion-irradiating the film or foil specimen normal to the major surfaces and observing in plan view (i.e., in essentially the same direction), the specimen is irradiated edge-on (i.e., parallel to the major surfaces) and is observed normal to the depth direction of the irradiation. The results of calculations utilizing the modified TRIM code are presented for cases of 200 and 500 keV Co impinging onto the edge of Si films 200 and 600 nm thick. The limitations of the technique are discussed and the feasibility of experiments involving implantation of Co into Si and the formation of COSi2, which employ this technique, are briefly discussed.

In Situ Fabrication and Characterization of (NiCr)Al-Al2O3 Nanocomposite by Mechanical Alloying

2012 ◽  
Vol 16 ◽  
pp. 21-27 ◽  
Author(s):  
Amir Reza Shirani-Bidabadi ◽  
Ali Shokuhfar ◽  
Mohammad Hossein Enayati ◽  
Mazda Biglari
Keyword(s):  
Electron Microscopy ◽  
Mechanical Alloying ◽  
Structural Changes ◽  
Formation Mechanisms ◽  
Cross Sectional ◽  
Molar Ratios ◽  
Transmission Electron ◽  
Powder Particles

In this research, the formation mechanisms of a (NiCr)Al-Al2O3 nanocomposite were investigated. The structural changes of powder particles during mechanical alloying were studied by X-ray difractometry (XRD) and the morphology and cross sectional microstructure of powder particles were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The methodology involved mechanical alloying of NiO, Cr, and Al with molar ratios of 3:3:8. During mechanical alloying, NiO was first quickly reduced by aluminum atoms to produce NiAl nanocrystalline and Al2O3. Subsequently, and when a longer milling time was applied, chromium atoms diffused into the NiAl lattice. The heat treatment of this structure led to the formation of the (NiCr)Al intermetallic compound as well as Al2O3 with crystalline sizes of 23 nm and 58 nm, respectively.

Nanometer-area diffraction of small iron crystallites in single crystalline Fe-MgO composite films

1988 ◽  
Vol 46 ◽  
pp. 706-707
Author(s):  
N. Tanaka ◽  
K. Mihama ◽  
H. Ou ◽  
J.M. Cowley
Keyword(s):  
Phase Transformation ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Carbon Film ◽  
Composite Films ◽  
High Resolution Electron Microscopy ◽  
Scanning Transmission Electron Microscope ◽  
Specimen Preparation ◽  
Single Crystalline ◽  
Transmission Electron

Nanometer-sized iron(Fe) crystallites can be prepared in a single crystalline magnesium oxide(MgO) film by a simultaneous vacuum deposition of Fe and MgO. The crystallites are grown epitaxially and almost coherently in the film, the orientation being (001) [110]Fe//(001)[100]MgOand (011) [100]Fe//(001) [100]MgO. A heat treatment of the as-grown composite films at 500-1000°C brings about a phase-transformation from α -iron(b.c.c.) to γ -iron(f.c.c.). In the present study, the phase-transformation and the structure of the γ-iron crystallites are studied by nanometer-area electron diffraction(nanodiffraction) in TEM and STEM as well as high-resolution electron microscopy.The specimens were single crystalline Fe-MgO composite films prepared on a NaCl (001 ) surface by co-evaporation of Fe and MgO. The films were separated from the substrate in water and mounted on a perforated carbon film. Nanodiffraction in TEM was performed in a 200 kV transmission electron microscope(JEM- 2000FX)2 and that in STEM3was carried out in a 100 kV scanning transmission electron microscope (VG-HB5) equipped with a specimen-preparation chamber.

A TEM study of low-temperature Ge growth on Ge(001)2×1

1993 ◽  
Vol 51 ◽  
pp. 804-805
Author(s):  
H.Z. Xiao ◽  
G. Xue ◽  
I.M. Robertson ◽  
H.K. Birnbaum ◽  
J.E. Greene
Keyword(s):  
Low Temperature ◽  
High Energy ◽  
Group Iv ◽  
Cross Sectional ◽  
Mbe Growth ◽  
Group Iv Semiconductors ◽  
Transmission Electron ◽  
And Control ◽  
Post Deposition

One approach to a solution of the doping problem in the molecular beam epitaxy (MBE) growth of the group IV semiconductors, e.g., segregation, low incorporation, and control of the dopants, is to lower the growth temperatures. It has been found that the room temperature Si deposition becomes amorphous after growth of a limiting epitaxial thickness which increases rapidly with the growth temperature. However, the mechanism for this structural transition is not well understood. In the present paper, we report the preliminary results of a study on the mechanism of the low temperature MBE growth of Ge on Ge(001)2×1 over the temperature range of 20-100 °C at deposition rates R=0.05 and 0.1 nm s−1 in an MBE system which has a bass pressure of 5xl0−11 Torr which increases to about 2xl0−9 Torr during deposition. The structural transitions were investigated using a combination of in-situ reflection high-energy electron diffraction (RHEED) and post-deposition high resolution cross-sectional transmission electron microscopy (XTEM).

The L12 to DO19 Phase Transformation In The Intermetallic Compound Fe3Ge

1997 ◽  
Vol 481 ◽  
Author(s):  
Q. Z. Chen ◽  
A. H. W. Ngan ◽  
B. J. Duggan
Keyword(s):  
Phase Transformation ◽  
Electron Microscope ◽  
Intermetallic Compound ◽  
Transmission Electron Microscope ◽  
Stacking Fault ◽  
Transmission Electron ◽  
Do19 Phase ◽  
Annealing Experiments

ABSTRACTA large kinetics hysteresis is found to exist between the forward and backward reactions of the L12 ↔ DO19 transformation in Fe3Ge. The slow DO19 to L12 transformation leaves behind very stable twins and stacking fault debris. In-situ annealing experiments in the transmission electron microscope revealed that nucleation for the reverse L12 to DO19 reaction takes place efficiently at these defects.

In Situ Observation of Electron Beam-Induced Phase Transformation of CaCO3 to CaO via ELNES at Low Electron Beam Energies

2014 ◽  
Vol 20 (3) ◽  
pp. 715-722 ◽  
Author(s):  
Ute Golla-Schindler ◽  
Gerd Benner ◽  
Alexander Orchowski ◽  
Ute Kaiser
Keyword(s):  
Phase Transformation ◽  
Electron Beam ◽  
Electron Microscope ◽  
Bond Length ◽  
Transmission Electron Microscope ◽  
Low Voltage ◽  
In Situ Observation ◽  
Edge Structure ◽  
Transmission Electron

AbstractIt is demonstrated that energy-filtered transmission electron microscope enables following of in situ changes of the Ca-L2,3 edge which can originate from variations in both local symmetry and bond lengths. Low accelerating voltages of 20 and 40 kV slow down radiation damage effects and enable study of the start and finish of phase transformations. We observed electron beam-induced phase transformation of single crystalline calcite (CaCO3) to polycrystalline calcium oxide (CaO) which occurs in different stages. The coordination of Ca in calcite is close to an octahedral one streched along the <111> direction. Changes during phase transformation to an octahedral coordination of Ca in CaO go along with a bond length increase by 5 pm, where oxygen is preserved as a binding partner. Electron loss near-edge structure of the Ca-L2,3 edge show four separated peaks, which all shift toward lower energies during phase transformation at the same time the energy level splitting increases. We suggest that these changes can be mainly addressed to the change of the bond length on the order of picometers. An important pre-condition for such studies is stability of the energy drift in the range of meV over at least 1 h, which is achieved with the sub-Ångström low-voltage transmission electron microscope I prototype microscope.

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