Ni ion-implanted α-Al2 O3

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Ni ion-implanted α-Al2 O3

Transcript of Ni ion-implanted α-Al2 O3

  • 1. Optical properties of metallic nanoparticles in Ni-ion-implanted -Al2O3 single crystals
    X. Xiang and X. T. Zu
    S. Zhu and L. M. Wang
    Younes Sina

2. Ion implantation
A powerful technique for forming nanoparticles
Potential promise as a means of modifying the near surface mechanical, electrical, optical, and magnetic properties in insulator materials due to quantum confinement effects
3. -Al2O3has been often used in microelectronic devices or as window materials
Single crystal Sapphire has a highthermal conductivity, volume resistivity, hardness and wear resistance, as well as a high upper use temperature.
The energy band gap is large (9 eV).
Sapphire is a transparent material having useful transmission of wavelengths in the range 0.2 to 5.5 microns. It is much stronger than glass and can be used as viewing windows in high pressure and vacuum applications.
4. 5x1016Ni+/cm2
64 keV
1 0 mm
Vacuum
1.8x10-3
Pa
15 mm
F
Broadband peaked at 400 nm due to SPR ofNi0
Crystal turning gray
as-implanted
electron-irradiated
as-grown
225 nm
250 nm
400 nm
Optical absorption spectra of as-grown, as-implanted and electron irradiated Al2O3crystals. A broadband peaked at 400 nm appeared in the Ni-implanted sample. (1)as-grown (2) electron-irradiated, and (3) as-implanted
14. Single crystal of -Al2O3 (rhombohedral) has a wide band gap (Eg9 eV). Therefore, its intrinsic absorption is in the ultraviolet wave band. Pure single crystals of -Al2O3 look colorless and transparent in the visible region. Then from 380-740 nm (visible wave band) its absorption spectrum is a smooth line.
intrinsic absorption
15. In general, ion implantation techniques used to form nanocrystals may be categorized as follows:

  • Room temperature implantation followed by high temperature annealing

16. Room temperature implantation at dosage above the threshold dose for spontaneous nanocrystals formation 17. Ion implantation at elevated temperatures