Transmission Electron Microscopy of Point-Defect Clusters in Neutron-Irradiated Metals. I. Copper

Transmission electron microscopy has been used to study the thermal annealing of radiation induced defect clusters in polycrystalline tungsten. Specimens were taken from cylindrical tensile bars which had been irradiated to a fast (E > 1 MeV) neutron fluence of 4.2 × 1019 n/cm2 at 70°C, annealed for one hour at various temperatures in argon, and tensile tested at 240°C in helium. Foils from both the unstressed button heads and the reduced areas near the fracture were examined.Figure 1 shows typical microstructures in button head foils. In the unannealed condition, Fig. 1(a), a dispersion of fine dot clusters was present. Annealing at 435°C, Fig. 1(b), produced an apparent slight decrease in cluster concentration, but annealing at 740°C, Fig. 1(C), resulted in a noticeable densification of the clusters. Finally, annealing at 900°C and 1040°C, Figs. 1(d) and (e), caused a definite decrease in cluster concentration and led to the formation of resolvable dislocation loops.

Download Full-text

Examination of Extra Electron Diffraction Spots Observed in Deuterium-Irradiated Silicon by Using Parallel Electron Beam Illumination

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100136052 ◽

1990 ◽

Vol 48 (2) ◽

pp. 490-491

Author(s):

Ryuichiro Oshima ◽

Shoichiro Honda ◽

Tetsuo Tanabe

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Silicon Single Crystal ◽

Mixed Solution ◽

Parallel Beam ◽

Defect Clusters ◽

Float Zone ◽

Transmission Electron ◽

Extra Electron ◽

Diffraction Patterns

In order to examine the origin of extra diffraction spots and streaks observed in selected area diffraction patterns of deuterium irradiated silicon, systematic diffraction experiments have been carried out by using parallel beam illumination.Disc specimens 3mm in diameter and 0.5mm thick were prepared from a float zone silicon single crystal(B doped, 7kΩm), and were chemically thinned in a mixed solution of nitric acid and hydrogen fluoride to make a small hole at the center for transmission electron microscopy. The pre-thinned samples were irradiated with deuterium ions at temperatures between 300-673K at 20keV to a dose of 1022ions/m2, and induced lattice defects were examined under a JEOL 200CX electron microscope operated at 160kV.No indication of formation of amorphous was obtained in the present experiments. Figure 1 shows an example of defects induced by irradiation at 300K with a dose of 2xl021ions/m2. A large number of defect clusters are seen in the micrograph.

Download Full-text

Diffraction contrast of small point-defect agglomerates as studied by transmission electron microscopy (TEM)

Journal of Applied Crystallography ◽

10.1107/s0021889875010308 ◽

1975 ◽

Vol 8 (2) ◽

pp. 223-223 ◽

Cited By ~ 1

Author(s):

M. Rühle

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Point Defect ◽

Diffraction Contrast ◽

Transmission Electron ◽

Small Point

Download Full-text

Point Defect Detector Studies of Ge+ Implanted Silicon upon Oxidation

MRS Proceedings ◽

10.1557/proc-262-253 ◽

1992 ◽

Vol 262 ◽

Cited By ~ 1

Author(s):

H. L. Meng ◽

S. Prusstn ◽

K. S. Jones

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Point Defect ◽

Point Defects ◽

Type Ii ◽

Dislocation Loops ◽

Furnace Annealing ◽

Plan View ◽

Atom Concentration ◽

Transmission Electron

ABSTRACTPrevious results [1] have shown that type II (end-of-range) dislocation loops can be used as point defect detectors and are efficient in measuring oxidation induced point defects. This study investigates the interaction between oxidation-induced point defects and dislocation loops when Ge+ implantation was used to form the type II dislocation loops. The type II dislocation loops were introduced via Ge+ implants into <100> Si wafers at 100 keV to at doses ranging from 2×1015 to l×1016/cm2. The subsequent furnace annealing at 900 °C was done for times between 30 min and 4 hr in either a dry oxygen or nitrogen ambient. The change in atom concentration bound by dislocation loops as a result of oxidation was measured by plan-view transmission electron microscopy (PTEM). The results show that the oxidation rate for Ge implanted Si is similar to Si+ implanted Si. Upon oxidation a decrease in the interstitial injection was observed for the Ge implanted samples relative to the Si implanted samples. With increasing Ge+ dose the trapped atom concentration bound by the loops actually decreases upon oxidation relative to the inert ambient implying oxidation of Ge+ implanted silicon can result in either vacancy injection or the formation of an interstitial sink.

Download Full-text