The Raman effects in γ-LiAlO2 induced by low-energy Ga ion implantation

Abstract

The tetragonal γ-LiAlO2 crystal, known as a promising solid breeding material in future fusion reactors, has attracted much attention for its irradiation effects. This work focused on the Raman effects in ion-implanted γ-LiAlO2. Ga ions of 30, 80 and 150keV were implanted on the z-cut γ-LiAlO2 sample surfaces at a fluence of 1×1014ions/cm2 or 1×1015ions/cm2. The average ion range varied from 230 to 910Å. The Raman spectra were collected from the implanted surfaces before and after the implantation. Evident changes were reflected in the Raman modes intensities, with abnormal increments for the most detected modes. According to the assignments of Raman modes, the Al-O vibration was enhanced to a greater extent than the Li-Al-O vibration, and the LiO4-AlO4 vibration gained a lesser enhancement. The discussion, including the factors of roughness, crystalline disorder and influence by Ga ions, attempts to explain the increments of Raman intensity.