Calculation of the recoilless γ-ray emission spectra from a substitutional cation impurity diffusing via the 〈001〉 channels in the rutile structure

AbstractResults and problems of the model for Josephson pulsars are summarized and discussed. In this model coherent radio emission is generated in the mantle of a neutron star by the Josephson effect. The matter from the mantle may flow along the magnetic field through cracks in the crust, forming a magnetized plasma wave guide. Radio emission propagates in this plasma flow as polarized normal wave-guide modes. A line-of-sight section gives the observed polarized structure of pulses. In some cases polarized X- and γ-ray emission may be generated in this flow in or over cracks. Such an approach allows us to avoid the typical problems and is in agreement with the main observational results.

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Expected γ ray emission spectra from the lunar surface as a function of chemical composition

Journal of Geophysical Research Atmospheres ◽

10.1029/jb078i026p05847 ◽

1973 ◽

Vol 78 (26) ◽

pp. 5847-5866 ◽

Cited By ~ 70

Author(s):

R. C. Reedy ◽

J. R. Arnold ◽

J. I. Trombka

Keyword(s):

Chemical Composition ◽

Lunar Surface ◽

Emission Spectra ◽

Γ Ray

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Nano-probe x-ray analysis and high-resolution imaging on planar defects in high-pressure synthesized infinite-layer superconductor

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171377 ◽

1994 ◽

Vol 52 ◽

pp. 728-729

Author(s):

Y. Y. Wang ◽

H. Zhang ◽

V. P. Dravid ◽

H. Zhang ◽

L. D. Marks ◽

...

Keyword(s):

High Pressure ◽

High Resolution ◽

Atomic Structure ◽

Emission Spectra ◽

High Resolution Electron Microscopy ◽

Planar Defects ◽

X Ray ◽

Infinite Layer ◽

Resolution Electron ◽

Resolution Imaging

Azuma et al. observed planar defects in a high pressure synthesized infinitelayer compound (i.e. ACuO2 (A=cation)), which exhibits superconductivity at ~110 K. It was proposed that the defects are cation deficient and that the superconductivity in this material is related to the planar defects. In this report, we present quantitative analysis of the planar defects utilizing nanometer probe xray microanalysis, high resolution electron microscopy, and image simulation to determine the chemical composition and atomic structure of the planar defects. We propose an atomic structure model for the planar defects.Infinite-layer samples with the nominal chemical formula, (Sr1-xCax)yCuO2 (x=0.3; y=0.9,1.0,1.1), were prepared using solid state synthesized low pressure forms of (Sr1-xCax)CuO2 with additions of CuO or (Sr1-xCax)2CuO3, followed by a high pressure treatment.Quantitative x-ray microanalysis, with a 1 nm probe, was performed using a cold field emission gun TEM (Hitachi HF-2000) equipped with an Oxford Pentafet thin-window x-ray detector. The probe was positioned on the planar defects, which has a 0.74 nm width, and x-ray emission spectra from the defects were compared with those obtained from vicinity regions.

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