Fine iron particles formed in a sapphire crystal by the ion implantation technique

Abstract

The magnetic properties of iron atoms implanted into a sapphire crystal at a dose from 4×1016 to 1×1017 Fe/cm2 were investigated using conversion electron Mössbauer spectroscopy at low temperature. It was confirmed that the components in the Mössbauer spectra which have been assigned to the Fe4+ state so far by other researchers are caused by fine particles of metallic iron, and about 75% of the implanted iron atoms stabilize in the form of fine particles of α iron at high implantation dose. Growth of the fine particles was simulated with a computer, and the expected Mössbauer spectra were calculated considering the influence of the nearest neighbors and next-nearest neighbors on the magnetic hyperfine field of the iron atoms. The simulated spectra agrees well with the experimentally observed spectra on the whole.

Mössbauer spectroscopy of 57Fe in α-Al2O3 following implantation of 57Mn*

“…Several authors [4][5][6] claimed that upon high fluence implantation (∼10 17 57 Fe/cm 2 ) Fe was observed in the 4+ valence state. This claim was disproved by low temperature measurements of Kobayashi et al [7] where it was shown that the spectral features assigned to Fe 4+ were due to fine particles of metallic iron.…”

Aggregation and out diffusion of iron atoms for Fe ion implanted silica films

“…Up to date, different techniques, such as melt quenching, 5 cosputtering, 4,6 ion exchange, 7 sol-gel, 8 ion implantation, [9][10][11][12] and so on, have been developed for promoting the formation of colloidal glasses containing metallic nanoclusters. Among these methods, ion implantation has proved to be very promising because of its simplicity and precise control over the microstructure of the nanocomposites, such as the quantities and depth profile of the implanted ions, the particle size and its distribution of the nanoclusters, and so on.…”

Ion-implantation-prepared catalyst nanoparticles for growth of carbon nanotubes

“…The growth in the size of Ni particles has been attributed to the mechanism of Ostwald ripening. [14][15][16] Following proper etching to expose Ni nanoparticles on the surface, the sample along with others was loaded in the CVD chamber for CNT growth under the same conditions. As seen in Fig.…”

“…This data trend is consistent with previous work using ion implantation to induce nucleation of transition metal nanoparticles in Si and SiO 2 . [14][15][16][17] Carbon nanotubes were successfully grown on these etched samples. SEM images ͑Fig.…”