On the temperature dependence of hydration thermodynamics for noble gases

Calculations of positron–atom and positron–molecule scattering are reviewed. The polarized orbital results of the York group are found to be of the same reliability as recent experimental determinations in the elastic region for the noble gases. The temperature dependence of the annihilation rate is suggested as a sensitive point of contact between theory and experiment. Using a new, direct experimental determination of the positronium formation cross section below the ionization threshold for argon and helium, we have made an improved Ore-type estimate of the positronium fraction of the noble gases. The new estimates agree perfectly with experiment for the three lighter gases. However, for krypton and xenon, the new estimates are much too high, which suggests the existence of an unknown process which suppresses or depletes positronium. Recent calculations on other atoms and on simple diatomic molecules are also reviewed.

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Temperature dependence of nuclear shielding and quadrupolar coupling of noble gases in liquid crystals

The Journal of Chemical Physics ◽

10.1063/1.463324 ◽

1992 ◽

Vol 97 (12) ◽

pp. 8977-8985 ◽

Cited By ~ 26

Author(s):

Juhani Lounila ◽

Oliver Muenster ◽

Jukka Jokisaari ◽

Peter Diehl

Keyword(s):

Liquid Crystals ◽

Temperature Dependence ◽

Noble Gases ◽

Quadrupolar Coupling ◽

Nuclear Shielding

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Temperature Dependence of Positron Annihilation Rates in Noble Gases

Physical Review Letters ◽

10.1103/physrevlett.77.2929 ◽

1996 ◽

Vol 77 (14) ◽

pp. 2929-2932 ◽

Cited By ~ 29

Author(s):

C. Kurz ◽

R. G. Greaves ◽

C. M. Surko

Keyword(s):

Temperature Dependence ◽

Positron Annihilation ◽

Noble Gases

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Temperature Dependence of the Critical Electron Dose for Fatty Acid Monolayers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053188 ◽

1982 ◽

Vol 40 ◽

pp. 78-79

Author(s):

Kenneth H. Downing ◽

Robert M. Glaeser

Keyword(s):

Electron Beam ◽

Fatty Acid ◽

Inelastic Scattering ◽

Temperature Dependence ◽

Structural Damage ◽

Direct Result ◽

Second Step ◽

Strong Temperature Dependence ◽

Electron Dose ◽

Covalent Bonds

The structural damage of molecules irradiated by electrons is generally considered to occur in two steps. The direct result of inelastic scattering events is the disruption of covalent bonds. Following changes in bond structure, movement of the constituent atoms produces permanent distortions of the molecules. Since at least the second step should show a strong temperature dependence, it was to be expected that cooling a specimen should extend its lifetime in the electron beam. This result has been found in a large number of experiments, but the degree to which cooling the specimen enhances its resistance to radiation damage has been found to vary widely with specimen types.

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Temperature Dependence of Magnetic Domains and Wall Structures

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010009573x ◽

1972 ◽

Vol 30 ◽

pp. 496-497

Author(s):

Sonoko Tsukahara ◽

Tadami Taoka ◽

Hisao Nishizawa

Keyword(s):

Temperature Dependence ◽

Domain Walls ◽

Magnetic Domain ◽

Iron Film ◽

Objective Lens ◽

Lorentz Microscopy ◽

Domain Structures ◽

Wall Structures ◽

Crystal Films ◽

Metallurgical Structure

The high voltage Lorentz microscopy was successfully used to observe changes with temperature; of domain structures and metallurgical structures in an iron film set on the hot stage combined with a goniometer. The microscope used was the JEM-1000 EM which was operated with the objective lens current cut off to eliminate the magnetic field in the specimen position. Single crystal films with an (001) plane were prepared by the epitaxial growth of evaporated iron on a cleaved (001) plane of a rocksalt substrate. They had a uniform thickness from 1000 to 7000 Å.The figure shows the temperature dependence of magnetic domain structure with its corresponding deflection pattern and metallurgical structure observed in a 4500 Å iron film. In general, with increase of temperature, the straight domain walls decrease in their width (at 400°C), curve in an iregular shape (600°C) and then vanish (790°C). The ripple structures with cross-tie walls are observed below the Curie temperature.

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