Lattice Location of Boron and Hafnium Dopants in an Aluminide by Use of Ion Channeling/Nuclear Reaactnio Analyses

1986 ◽  
Vol 81 ◽  
Author(s):  
H. G. Bohn ◽  
J.M. Williams ◽  
J.H. Barrett ◽  
C.T. Liu
Keyword(s):  
Single Crystal ◽  
Nuclear Reaction ◽  
Nickel Aluminide ◽  
Host Lattice ◽  
Alpha Particles ◽  
Alloy Single Crystal ◽  
Lattice Location ◽  
Reaction Products ◽  
Ion Channeling ◽  
Proton Interaction

AbstractExperiments have made use of Rutherford backscattering (RBS), ion channeling techniques and analyses for nuclear reaction products to study lattice location of B and Hf dopantsin an ordered nickel aluminide. Studies were of an alloy single crystal of composition Ni76A123Hf1 with about 0.1 at. % of B added. Analysis for B was accomplished by detection of alpha particles resulting from the reaction 11B(p,αi)8 Be, in ion channeling experiments in which RBS from the Ni constituent was used to control channeling in the host lattice. Yield of the reaction product from proton interaction with B decreased relative to random for channeling in a <100> direction, but increased relative to random for channeling in a <110= direction. It was concluded that B occupies primarily octahedral interstitial sites. RBS/channeling half-angles for Hf in a <100> direction are somewhat smaller than those for Ni, but nevertheless considerably larger than half-angles expected for Al. It is concluded that the majority of Hf atoms are on the Ni sublattice.

scholarly journals Optical Radiation from the Sputtered Species under Excitation of Ternary Mixtures of Noble Gases by the 6Li(n,α)3H Nuclear Reaction Products

2021 ◽  
Vol 23 (2) ◽  
pp. 95
Author(s):  
K. Samarkhanov ◽  
M. Khasenov ◽  
E. Batyrbekov ◽  
Yu. Gordienko ◽  
Yu. Baklanova ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Nuclear Reaction ◽  
Alkali Metals ◽  
Nuclear Reactor ◽  
Noble Gases ◽  
Noble Gas ◽  
Alpha Particles ◽  
Ternary Mixtures ◽  
Reaction Products ◽  
Energy Excitation

The present paper examines the luminescence of ternary Ar-Kr-Xe and Ne-Ar-Kr mixtures of noble gases in the spectral range from 300 to 970 nm, excited by the 6Li(n,α)3H nuclear reaction products in the core of a nuclear reactor. A thin layer of lithium applied on the walls of the experimental device, stabilized in the matrix of the capillary-porous structure, serves as a source of gas excitation. During in-pile tests, conducted at the IVG.1M research reactor, thermal neutrons interact via the 6Li(n,α)3H reaction, and the emergent alpha particles with a kinetic energy of 2.05 MeV and tritium ions with a kinetic energy of 2.73 MeV excite gaseous medium. The study was carried out in a wide temperature range. The temperature dependence of the intensity of the emission of the atoms of noble gases and alkali metals, heteronuclear ionic molecules of noble gases were studied. The obtained values of the activation energy of the emission process 1.58 eV for lithium and 0.72 eV for potassium agree well with the known values of evaporation energy. Excitation of alkali metals atoms occurs consequently of the Penning process of alkali metals atoms on noble gas atoms in the 1s-states and further ion-molecular reactions.

Lattice Location of Ta in Ni3Ai by Ion Channeling and Nuclear Reaction Analysis

1986 ◽  
Vol 81 ◽  
Author(s):  
H. Lin ◽  
L. E. Sehberling ◽  
P. F. Lyman ◽  
D. P. Pope
Keyword(s):  
Nuclear Reaction ◽  
Ternary Phase Diagram ◽  
Liquid Scintillator ◽  
Ion Beam ◽  
Lattice Location ◽  
Nuclear Reaction Analysis ◽  
Surface Barrier ◽  
Crystallographic Axis ◽  
Ion Channeling ◽  
Barrier Detector

AbstractWe have investigated the lattice location of Ta in Ni3Al using Rutherford backscattering with channeling, and nuclear reaction analysis. An 8 MeV 4He ion beam was directed along the < 100> crystallographic axis of the Ni75Al24Ta single crystal. A silicon surface barrier detector was used to analyze 4He ions backscattered from Ni and Ta atoms. Neutrons generated from Al by the 27Al(4He,n)30P reaction were detected by a large volume liquid scintillator placed outside of the scattering chamber. Essentially all of the Ta atoms were found to be substitutional, as determined by the Ta channeling minimum yield. A comparison of the width of the channeling angular scan for Al, Ni and Ta indicated that the Ta atoms are predominantly distributed on the Ni sites. This result is in conflict with expectations based on the ternary phase diagram.

Studies of Oxide Formation on Copper Thin Films by Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 316-317
Author(s):  
G. G. Hembree ◽  
M. A. Otooni ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Crystal Surface ◽  
Crystal Defects ◽  
Diffraction Reflection ◽  
Reaction Products ◽  
Intermediate Energies ◽  
Crystal Films ◽  
Reflection Electron Microscopy

The formation of oxide structures on single crystal films of metals has been investigated using the REMEDIE system (for Reflection Electron Microscopy and Electron Diffraction at Intermediate Energies) (1). Using this instrument scanning images can be obtained with a 5 to 15keV incident electron beam by collecting either secondary or diffracted electrons from the crystal surface (2). It is particularly suited to studies of the present sort where the surface reactions are strongly related to surface morphology and crystal defects and the growth of reaction products is inhomogeneous and not adequately described in terms of a single parameter. Observation of the samples has also been made by reflection electron diffraction, reflection electron microscopy and replication techniques in a JEM-100B electron microscope.A thin single crystal film of copper, epitaxially grown on NaCl of (100) orientation, was repositioned on a large copper single crystal of (111) orientation.

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