Sharma, S. K. Kumar, P. Kumar, Ravi Knobel, M. Thakur, P. Chae, K. H. Choi, W. K. Kumar, R. Kanjilal, D. 2024-01-20T23:02:12Z 2024-01-20T23:02:12Z 2021-09-03 2008-07-16 0953-8984 https://pubs.kist.re.kr/handle/201004/133318 This work reports the formation of Ni nanostructures, their growth and saturation to form oxides by using ion implantation and thermal treatment in air at 600 degrees C. A quartz (SiO2) matrix was implanted with 100 keV Ni+ ions to doses in the range 5 x 10(15) -2 x 10(17) ions cm(-2). The formation of Ni nanoclusters was observed by high resolution x-ray diffraction (HRXRD), UV-visible optical spectroscopy, dc magnetization, AFM/ MFM and x-ray absorption spectroscopy (XAS). The cluster size distribution is narrow, with an average size of similar to 25 +/- 0.5 nm for the sample implanted at a dose of 1 x 10(16) ions cm(-2), but increases with implantation dose. Optical absorption spectra also show a clear signature of a surface plasmon resonance (SPR) peak at around 388 nm in accordance with the theoretical Mie's spectra. Temperature dependent zero-field-cooled and field-cooled magnetization measurements clearly indicate a superparamagnetic behavior, which is properly analyzed considering the size distribution of the magnetic nanostructures. The results show that the magnetic properties of the nanoparticles can be controlled by the implantation dose. A detailed investigation of the local structure using Ni K-edge NEXAFS/EXAFS suggests that the size of the Ni nanostructures is altered by implantation dose, reaching saturation in the form of oxides/silicates of Ni at a dose of 2 x 10(17) ions cm(-2). English IOP PUBLISHING LTD X-RAY-ABSORPTION SILICA GLASS NICKEL SPECTROSCOPY PARTICLES FILMS CO PHOTOEMISSION OXIDATION VALENCE Local structure, optical and magnetic studies of Ni nanostructures embedded in a SiO2 matrix by ion implantation Article 10.1088/0953-8984/20/28/285211 1 JOURNAL OF PHYSICS-CONDENSED MATTER, v.20, no.28 JOURNAL OF PHYSICS-CONDENSED MATTER 20 28 scie scopus 000257178500021 2-s2.0-47249153481 Physics, Condensed Matter Physics Article X-RAY-ABSORPTION SILICA GLASS NICKEL SPECTROSCOPY PARTICLES FILMS CO PHOTOEMISSION OXIDATION VALENCE Ni nanostructures ion implantation x-ray absorption spectroscopy