Spectroscopic studies of swift heavy ion irradiated nanophase mullite

Photoluminescence (PL) studies of 100 MeV swift Ag8+ ion bombarded combustion synthesized nanophase mullite has been studied at room temperature (RT) and the results are reported here. A pair of PL bands, one broad band centres at ∼550 nm and another sharp one at ∼690 nm are observed with excitation by a 442 nm laser beam. However, when the sample is excited with 326 nm laser beam, three bands with peaks at ∼460, 550 and a well resolved one with peak at 760 nm are observed. It is observed that the PL intensity increases up to 5 x 1011 ions/cm2 and thereafter it decreases with increase of ion fluence. The pristine as well as Ag8+ ion irradiated mullites are characterized by infrared spectroscopy (IR) and X-ray diffraction (XRD) techniques. The decrease in PL intensity is attributed to Al-O and Si-O bonds present as the surface getting amorphized. The effects of Ag8+ irradiation are compared to those obtained with Ni8+ ions and the results are discussed