Microstructure and properties of embedded nanocrystals formed by ion implantation
Abstract
Ion implantation is an attractive technique for synthesizing embedded metallic and semiconducting nanocrystals. The ion implantation method is highly versatile and can be used to create many types of nanoparticles embedded in a wide variety of host materials. The nucleation and growth mechanisms of the particles produced by the implantation method are, however, highly complex. This complexity frequently leads to bimodal size distributions and peculiar microstructures, in some cases resulting in unexpected optical or magnetic effects. Observations of unusual microstructures will be presented and discussed. Radiation effects that occur in the host during implantation are found to play a critical role in determining the microstructure of the nanocrystal precipitates, as well as their crystal structure, morphology, orientation, size, and size distribution. An understanding of the effects of irradiation on the nucleation and growth processes creates the potential to control the microstructure and properties of the nanoparticles. Experiments demonstrate that radiation effects can be used in at least three ways, including: i) to cause direct irradiation-induced phase decomposition to produce monodispersed particles, ii) to stimulate nucleation and growth of nanoparticles in doped (i.e., impure) host materials, and iii) to create irradiation-induced microstructural modifications of phases containing pre-existing nanoparticles. These three methods can be used to tailor the microstructure and size distribution of the particles and can lead to pronounced magnetic or optical effects.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2000
- Bibcode:
- 2000APS..MARB29001M