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1.
L.M. Zhang C.H. Zhang L.Q. ZhangX.J. Jia T.D. MaY. Song Y.T. YangB.S. Li Y.F. Jin 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(15):1782-1785
Wurtzite GaN epilayers irradiated at room temperature with 308 MeV 129Xe35+ ions to fluences of 1 × 1013 and 3 × 1013 cm−2 have been studied by contact mode atomic force microscopy (AFM), high-resolution X-ray diffraction (HRXRD), micro-Raman scattering and photoluminescence (PL) spectroscopy. The AFM images showed that the surface of GaN films was etched efficiently due to the Xe ion irradiation. The initial step-terrace structure on GaN surface was eliminated completely at a fluence of 3 × 1013 cm−2. HRXRD and Raman results indicated that the Xe ion irradiation led to a homogenous lattice expansion throughout the entire ∼3 μm-thick GaN films. The lattice expansion as well as the biaxial compressive stress of the films was increasing with the increase of ion fluence. PL measurements showed that a dominant yellow luminescence band in the as-grown GaN films disappeared, but a blue and a green luminescence bands were produced after irradiation. Based on these results, the strong electronic excitation effect of 308 MeV Xe ions in GaN is discussed. 相似文献
2.
《Journal of Nuclear Science and Technology》2013,50(4):313-319
Bending and compressive strengths, and Young's modulus were measured for Pechiney nuclear grade graphite irradiated in the temperature range 220~400°C in the environment of CO2 in a commercial reactor, up to the neutron fluence 6.2 × 1019 and 2.2 × 1020n/cm2 (E>0.85 MeV), respectively. All of them increased owing to neutron irradiation, and the changes in both strengths were almost similar in the whole range of irradiation temperature, however the changes in Young's modulus depended on irradiation temperature. It was clarified in the present experiment that both strengths were related with Young's modulus and the relation could be expressed by the formula σ=kE n, where σ and E are strength and Young's modulus, respectively, and n is constant which has different value for bending or compressive strength and also for their measured direction. 相似文献