Shift of phonon anomaly withTcobserved in (Y,Er)Ba2Cu3O7−δby ion channeling

1989 ◽  
Vol 40 (16) ◽  
pp. 11396-11399 ◽  
Author(s):  
R. P. Sharma ◽  
L. E. Rehn ◽  
P. M. Baldo ◽  
J. Z. Liu
Keyword(s):  
Ion Channeling ◽  
Phonon Anomaly

Phonon Anomaly at Tc In (Y/Er)Ba2Cu3O7–δ

1989 ◽  
Vol 169 ◽  
Author(s):  
Rajeshwar P. Sharma ◽  
L. E. Rehn ◽  
P. Baldo ◽  
J. Z. Liu
Keyword(s):  
Transition Temperature ◽  
Single Crystals ◽  
Superconducting Transition Temperature ◽  
Structural Changes ◽  
Abrupt Change ◽  
Superconducting Transition ◽  
Ion Channeling ◽  
Atomic Displacements ◽  
Induced Changes ◽  
Phonon Anomaly

AbstractIon channeling in single crystals of (Y/Er)Ba2Cu3O7–δ reveal an abrupt change (~0.01Å) at the superconducting transition temperature (Tc) in displacements of the Cu and O atoms perpendicular to the [001] direction. This anomalous change in atomic displacements shifts directly with stoichiometry-induced changes in Tc. Blocking patterns indicate no large structural changes across Tc.

Scanning ion microscopy images

1987 ◽  
Vol 45 ◽  
pp. 180-181
Author(s):  
R. Levi-Setti ◽  
J.M. Chabala ◽  
Y.L. Wang
Keyword(s):  
Metal Ion ◽  
Secondary Emission ◽  
Scanning Method ◽  
Ion Channeling ◽  
Secondary Ions ◽  
High Resolution Images ◽  
Ion Microscopy ◽  
Z Contrast ◽  
Focused Beams ◽  
Microscopy Images

Finely focused beams extracted from liquid metal ion sources (LMIS) provide a wealth of secondary signals which can be exploited to create high resolution images by the scanning method. The images of scanning ion microscopy (SIM) encompass a variety of contrast mechanisms which we classify into two broad categories: a) Emission contrast and b) Analytical contrast.Emission contrast refers to those mechanisms inherent to the emission of secondaries by solids under ion bombardment. The contrast-carrying signals consist of ion-induced secondary electrons (ISE) and secondary ions (ISI). Both signals exhibit i) topographic emission contrast due to the existence of differential geometric emission and collection effects, ii) crystallographic emission contrast, due to primary ion channeling phenomena and differential oxidation of crystalline surfaces, iii) chemical emission or Z-contrast, related to the dependence of the secondary emission yields on the Z and surface chemical state of the target.

scholarly journals The Examination of Calcium ion Implanted Alumina with Energy Filtered Transmission Electron Microscopy

1997 ◽  
Vol 3 (S2) ◽  
pp. 413-414
Author(s):  
E.M. Hunt ◽  
J.M. Hampikian ◽  
N.D. Evans
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Pure Aluminum ◽  
Lattice Parameter ◽  
Face Centered Cubic ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Knoop Microhardness ◽  
Aluminum Nanocrystals ◽  
Face Centered

Ion implantation can be used to alter the optical response of insulators through the formation of embedded nano-sized particles. Single crystal alumina has been implanted at ambient temperature with 50 keV Ca+ to a fluence of 5 x 1016 ions/cm2. Ion channeling, Knoop microhardness measurements, and transmission electron microscopy (TEM) indicate that the alumina surface layer was amorphized by the implant. TEM also revealed nano-sized crystals ≈7 - 8 nm in diameter as seen in Figure 1. These nanocrystals are randomly oriented, and exhibit a face-centered cubic structure (FCC) with a lattice parameter of 0.409 nm ± 0.002 nm. The similarity between this crystallography and that of pure aluminum (which is FCC with a lattice parameter of 0.404 nm) suggests that they are metallic aluminum nanocrystals with a slightly dilated lattice parameter, possibly due to the incorporation of a small amount of calcium.Energy-filtered transmission electron microscopy (EFTEM) provides an avenue by which to confirm the metallic nature of the aluminum involved in the nanocrystals.

Phonon anomaly of La1.85Sr0.15CuO4 studied by neutron scattering

1995 ◽  
Vol 213-214 ◽  
pp. 75-77 ◽  
Author(s):  
M. Arai ◽  
K. Yamada ◽  
S. Hosoya ◽  
S. Wakimoto ◽  
K. Ubukata ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Phonon Anomaly

ION CHANNELING AND PIXE STUDIES OF S IMPLANTATION IN GaAs

1992 ◽  
Vol 02 (02) ◽  
pp. 151-159
Author(s):  
LIU SHIJIE ◽  
WANG JIANG ◽  
HU ZAOHUEI ◽  
XIA ZHONGHUONG ◽  
GAO ZHIGIANG ◽  
...  
Keyword(s):  
Room Temperature ◽  
Dislocation Loops ◽  
Good Recovery ◽  
Electrical Measurements ◽  
X Ray ◽  
Defect Complexes ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Activation Efficiency ◽  
Very High

GaAs (100) crystals were implanted with 100 keV S+ to a dose of 3×1015 cm−2 in a nonchanneling direction at room temperature, and treated with rapid thermal annealing (RTA). He+ Rutherford backscattering and particle-induced X-ray emission in channeling mode in combination with transmission electron microscopy (TEM) were used to study the damage and the lattice location of S atoms. It is revealed that the RTA at 950 °C for 10 sec has resulted in a very good recovery of crystallinity with a few residual defects in the form of dislocation loops, and a very high substitutionality (~90%). The activation efficiency and the Hall mobility of the implanted samples are found to be low after the electrical measurements. Based on these results an extended dopant diffusion effect for the residual defects and a correlation between the electrical properties and defect complexes are suggested.

Two modes of Ga diffusion into InAs self-assembled quantum dots suggested by ion channeling

2002 ◽  
Vol 13 (2-4) ◽  
pp. 1168-1171 ◽  
Author(s):  
N Matsumura ◽  
T Haga ◽  
S Muto ◽  
Y Nakata ◽  
N Yokoyama ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ion Channeling ◽  
Self Assembled

Quantum effects in ion channeling

1972 ◽  
Vol 12 (3-4) ◽  
pp. 149-152 ◽  
Author(s):  
F. Grasso ◽  
M. Lo Savio ◽  
E. Rimini
Keyword(s):  
Quantum Effects ◽  
Ion Channeling

Solute Segregation and Dynamics of Solid-Phase Crystallization In in and Sb-Implanted Silicon

1981 ◽  
Vol 4 ◽  
Author(s):  
J. Narayan ◽  
G. L. Olson ◽  
O. W. Holland
Keyword(s):  
Laser Power ◽  
Solid Phase ◽  
Solute Segregation ◽  
Dislocation Loops ◽  
Solid Phase Crystallization ◽  
Time Resolved ◽  
Plan View ◽  
Ion Channeling ◽  
Retrograde Solubility ◽  
Transmission Electron

ABSTRACTTime-resolved-reflectivity measurements have been combined with transmission electron microscopy (cross-section and plan-view), Rutherford backscattering and ion channeling techniques to study the details of laser induced solid phase epitaxial growth in In+ and Sb+ implanted silicon in the temperature range from 725 to 1500 °K. The details of microstructures including the formation of polycrystals, precipitates, and dislocations have been correlated with the dynamics of crystallization. There were limits to the dopant concentrations which could be incorporated into substitutional lattice sites; these concentrations exceeded retrograde solubility limits by factors up to 70 in the case of the Si-In system. The coarsening of dislocation loops and the formation of a/2<110>, 90° dislocations in the underlying dislocation-loop bands are described as a function of laser power.

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