The formation mechanism of periodic Zn nanocrystal arrays embedded in an amorphous layer by rapid electron beam irradiation

Abstract

A periodic nano-island array of ∼7 nm diameter Zn single crystals embedded in an amorphous Zn(2x)Si(1-x)O(2) layer was created by using rapid electron beam irradiation for 50 s. A sequential process of 900 °C thermal annealing followed by electron beam irradiation induces the formation of an amorphous Zn(2x)Si(1-x)O(2) layer containing periodic Zn nanocrystals. It is shown that the periodic Zn crystal array can be produced with good control of their size and spacing. Possible formation mechanisms for the Zn crystal nano-islands are described on the basis of the experimental results.

Electron-Irradiation Induced Nanocrystallization of Pb(II) in Silica Gels Prepared in High Magnetic Field

“…By EI zinc nonocrystal islands were formed in a SiO 2 layer [17]. Moreover, periodic zinc nanocrystal arrays were formed in an amorphous ZnSiO layer by EI [18]. In those studies the matrix is a non-crystalline insulator (oxide), which is same as in the present study.…”

Formation mechanisms of ZnO nanocrystals embedded in an amorphous Zn2xSi1−xO2 layer due to sputtering and annealing

“…The EDS spectrum demonstrated that the formed layer at the ZnO/Si heterointerface region consisted of Zn, Si, and O atoms, indicative of the formation of the Zn 2x Si 1−x O 2 layer. The formation of the amorphous Zn 2x Si 1−x O 2 layer was attributed to an interdiffusion of Zn, O, and Si atoms existing in the heterointerface region due to thermal treatment, resulting in the concomitant increase in the thickness of the amorphous interface layer [25,26]. The crystalline ZnO nanocrystals with sizes of 5-8 nm were embedded in the amorphous oxide layer, as determined from the HRTEM images shown in Fig.…”

“…The TEM measurements were performed using a Tecnai F30 S-twin transmission electron microscope operating at 300 keV [25]. The samples for the cross-sectional TEM measurements were prepared by cutting and polishing them to a thickness of approximately 30 m and then argon-ion milling at liquid-nitrogen temperature to electron transparency.…”

Electron-beam-induced formation mechanisms for Ti2O3–SiO2composite nanofibers

“…Therefore, the suboxide SiO x layer prefers to take oxygen from MO x (0 < x < 1) and to oxidize into a more stable SiO 2 matrix, resulting in the deoxidation of MO. 15,29) Therefore, the SiO 2 matrix helps MO to reduce into MO x (0 < x < 1), resulting in the enhancement of the reduction of MO in the MO-SiO 2 nanofiber rather than the MO nanoparticles. Because the heat of formation of SiO 2 is more negative than that of ZnO, 29) the ZnO nanoparticles embedded in the SiO 2 matrix are fully deoxidized during electron-beam irradiation.…”