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Abstract: Modifications of the C70 molecule (fullerene) under swift heavy ion irradiation are investigated. C70 thin films were irradiated with 120MeV Au ions at fluences from 1×1012 to 3×1013 ions/cm2. The energetic ion impacts lead to the destruction of the C70 molecule. To investigate the stability of C70 fullerene, the damage cross-section and radius of the damaged cylindrical zones are evaluated by fitting the evanescence of C70 vibration modes recorded by Raman spectroscopy. Conductivity measurements together with Raman and optical absorption studies revealed that an irradiation fluence of 3×1013 ions/cm2 results in complete amorphization of the carbon structure of the fullerene molecules. [Copyright &y& Elsevier]

Abstract: Thermally evaporated ZnO thin films have been irradiated with 100MeV Au8+ ions at different fluence from 5×1011 ions/cm2 to 5×1013 ions/cm2. The optical and structural properties of the irradiated and pristine films were studied using Fourier transform infrared spectroscopy (FTIR), UV–visible absorption spectroscopy, photoluminescence (PL), atomic force microscopy (AFM) and XRD. FTIR results showed that for low fluence, the transmittance of the film decreased and increased again at higher fluence but Zn–O bond remains unaffected by irradiation. As revealed from the absorption spectra, absorption edge is not changed by the irradiation but the optical absorption is increased. The AFM study of the films implied that roughness decreased at low fluence values up to 5×1012 ions/cm2 and at higher fluences the roughness increased. [Copyright &y& Elsevier]

Abstract: Thin films with ZnO nanocrystals in silica were synthesized by rf reactive magnetron co-sputter deposition and post-annealing. The films were deposited from a ZnO/Si composite target in an rf oxygen plasma. The deposited films were annealed in air/vacuum at high temperatures to grow ZnO nanocrystals. The deposited and annealed films were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), uv–vis spectroscopy (UV–VIS) and photoluminescence (PL) measurements. FT-IR results of the films show the vibrational features of Si–O–Si and Zn–O bonds. UV–VIS spectra of the deposited film shows the band edge of ZnO. The XRD results of the films annealed at 750°C and 1000°C indicate the growth of ZnO nanocrystals with average crystallite sizes between 7nm and 26nm. PL measurements of the deposited film show a broad visible luminescence peak which can be due to ZnO. These results suggest the growth of ZnO nanocrystals in silica matrix. [Copyright &y& Elsevier]