Secondary electron emission from oxides: Part III. HT superconductors

Tomashpolsky, Yu. Ya.; Sadovskaya, N. V.

doi:10.1080/00150199508208271

Cited by 4 publications

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the electron irradiated area an increase of the SEE yield has been observed. effect was also found in irradiated YBCO [23], and can be explained as a result of the electron irradiation induced changes in the cationic composition and oxygen losses [17]. According to the results summarized in figures 11-13, the increase of the SEE yield could be partially due to the reduction of oxygen content during irradiation.…”

Section: Discussionmentioning

confidence: 81%

“…In the present work the effect of electron irradiation on Tl 2 Ba 2 CuO 6+δ samples has been investigated in the SEM by using CL microscopy, energy dispersive xray microanalysis (EDX) and secondary-electron emission (SEE). SEE has been used in recent years in phase analysis on the grain scale, in the determination of oxygen content, and in the detection of phase transitions in YBCO and BSCCO ceramics and single crystals [15][16][17][18]. The exponential dependence of the SEE yield on the oxygen concentration explains the high sensitivity of this technique in the local determination of oxygen deficiency.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Electron beam induced compositional and structural changes in

Dı́az-Guerra

Piqueras

Tomashpolsky

et al. 1996

Supercond. Sci. Technol.

View full text Add to dashboard Cite

Tl 2 Ba 2 CuO 6+δ ceramics have been irradiated in a scanning electron microscope. The resultant changes in the cationic stoichiometry and oxygen content of the samples were investigated by cathodoluminescence (CL), secondary electron emission (SEE) and EDX microanalysis. Tl depletion and Ba enrichment are observed in the irradiated areas. CL spectroscopy shows that irradiation causes the increase of a 540 nm emission band attributed to complex centres involving oxygen vacancies. Other features of the CL spectra strongly suggest the presence of radiation induced new phases. The SEE yield, , has been found to depend on the oxygen content of the samples. This dependence can be explained on the basis of two charge carrier subsystems and their mutual interaction. Measurements of allow us to detect an oxygen deficient region, sometimes extending up to a distance of about 1000 µm, that surrounds the irradiated material.

show abstract

Section: Discussionmentioning

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Electron beam induced compositional and structural changes in

Dı́az-Guerra

Piqueras

Tomashpolsky

et al. 1996

Supercond. Sci. Technol.

View full text Add to dashboard Cite

show abstract

Cathodoluminescence Microscopy and Secondary Electron Emission in Mechanically Polished and Electron Irradiated YBa2Cu3O7−x Ceramics

Dı́az-Guerra

Piqueras

Tomashpolsky

et al. 1996

Phys. Stat. Sol. (a)

Self Cite

View full text Add to dashboard Cite

Cathodoluminescence (CL) and secondary electron emission (SEE) in the scanning electron microscope have been used to study the effects of mechanical polishing and electron irradiation on YBa2Cu3O7‐x ceramics. CL spectra from the mechanically polished superconductors show an enhanced 2.4 eV luminescence band, which is related to oxygen content redistribution or depletion. Electron irradiation induces strong morphological and compositional changes which are proposed to be connected with melting‐resolidification processes and surface phase segregation. SEE yield measurements allow to detect an oxygen depleted area with stoichiometric cationic composition surrounding the irradiated region. CL spectra recorded from this oxygen‐deficient area also show an enhanced 2.3 to 2.4 eV emission band in comparison with the spectra recorded from the non‐irradiated material. Strongly luminescent non‐superconducting phases appear in the irradiated regions, showing intense 3.1 and 0·78 to 0·81 eV emission bands.

show abstract

Structural and composition changes in superconducting ceramics locally irradiated by electrons

et al. 1997

Self Cite

View full text Add to dashboard Cite

The structural changes and the cation and anion compositions of the surface of superconducting YBa 2 Cu 3 O 7-x and Tl 2 Ba 2 CuO 6+x ceramics after local irradiation for several seconds by an electron probe with an accelerating voltage of 25 kV and a current exceeding 10 -7 A are investigated by secondary-electron emission and by cathodoluminescence and x-ray microanalysis in a scanning electron microscope. Morphologically altered regions are detected in the irradiation epicenter, where the structure, chemical composition, and phase composition of the original compound are completely lost. In the intermediate zone between the epicenter and the periphery a distribution of the secondary emission yield is observed with a complex character that differs for the yttrium and thallium ceramics, and anomalies appear in the cathodoluminescence spectra. The experimental data are interpreted on the basis of ideas of oxygen losses under the direct influence of the electron probe and related electronic processes in superconductors.

show abstract

Secondary electron emission from oxides: Part III. HT superconductors

Cited by 4 publications

References 3 publications

Electron beam induced compositional and structural changes in

Electron beam induced compositional and structural changes in

Cathodoluminescence Microscopy and Secondary Electron Emission in Mechanically Polished and Electron Irradiated YBa2Cu3O7−x Ceramics

Structural and composition changes in superconducting ceramics locally irradiated by electrons

Contact Info

Product

Resources

About