0000000000594334

AUTHOR

Yu. S. Kovalev

Mechanism of pulsed electron irradiation of the PLZT X/65/35 ceramics

The comprehensive study of high-current pulsed electron irradiation effect on the structure and lattice dynamics as well as Atomic Force (AFM) and Laser Confocal Scanning microscope (LSCM) surface imaginaries of PLZT 8/65/35 ceramics have been performed. X-ray powder diffraction studies show the transformation of the cubic perovskite Pm-3m (Z = 1) into orthorhombic Pmmm (Z = 1) structure for the sample irradiated by one pulse (dose 6 × 1014 electrons/cm2) and into cubic Pm-3m with increased lattice volume and more ordered structure at irradiating by 10 and 100 pulses (dose 6 × 1015 and 6 × 1016 el/cm2). A consequence, the changes of number, intensity and phonon modes position occur in Raman…

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In situ and postradiation analysis of mechanical stress in Al2O3:Cr induced by swift heavy-ion irradiation

Abstract Optical spectroscopy and TEM techniques have been applied to study the radiation damage and correlated mechanical stresses in Al2O3 and Al2O3:Cr single crystals induced by (1–3) MeV/amu Kr, Xe and Bi ion irradiation. Mechanical stresses were evaluated in situ using a piezospectroscopic effect through the shift of the respective lines in ionoluminescence spectra. It was found that dose dependence of the stress level for Xe and Bi ions, when ionization energy loss exceeds the threshold of damage formation via electronic excitations, exhibits several alternate stages showing the build-up and relaxation of stresses. The beginning of relaxation stages is observed at fluences associated …

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Piezospectroscopic study of mechanical stress in Al2O3:Cr under swift heavy ion irradiation

Abstract The spatial distribution of mechanical stresses in Al2O3:Cr single crystal irradiated with (1 ÷ 3) MeV/amu Kr, Xe and Bi ions has been studied by using laser confocal scanning microscopy technique. The stress level as a function of the ion penetration depth has been evaluated from depth-resolved photostimulated R-line luminescence spectra exploiting the piezospectroscopic method. As it was found, the stress field generated by swift heavy ion irradiation is composed of stresses with maximal magnitude comparable with the ultimate stress limit of ruby crystals. Experimental data are discussed in the framework of a model considering the Cr3+ atoms as individual piezosensors.

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