Microsc. Microanal. Microstruct. 8, 403-411 (1997)
DOI: 10.1051/mmm:1997131

Electron Beam Induced Structural Modification of the Oxidized Silicon Micro-Clusters in ZnO Matrix

Umadapa Pal¹, Naoto Koshizaki², Shin-ya Terauchi² et Takeshi Sasaki<sup>2

1</sup>  Instituto de Física, Universidad Autónoma de Puebla, Apdo. Postal J-48, Puebla, Pue. 72570, Mexico
²  National Institute of Materials and Chemical Research (NIMC), AIST, MITI, 1-1 Higashi, Tsukuba, Ibaraki 305, Japan

Abstract
Si/ZnO nano- and micro-composites were grown on SiO₂ glass substrates by co-sputtering technique. The content of Si in the films was controlled by the no. of Si pieces placed on the ZnO target. The crystallinity of the composite films decreased on increasing the Si content in them and increased on post deposition thermal annealing. The dispersed Si in the ZnO matrix remained in the form of nano-particles with an average size value of 3.7 nm and does not depend on the fractional Si content in them. On thermal annealing, the size of the nano-particles did not change noticeably up to 600°C. For the thermal annealing at and above 700°C, the nano-particles aggregated to form micro-clusters with an average size value of 34 nm. The micro-clusters were seen to be crystallized with distinct line structures in the TEM images and spots in the TED patterns. On high energy electron irradiation, the micro-clusters broke to form nano-particles of similar size as they were before the formation of micro-clusters.

PACS
6146 - Structure of solid clusters, nanoparticles, and nanostructured materials.
6480G - Microstructure.
6170A - Annealing processes.
6180F - Electron and positron effects.

Key words
annealing -- electron beam effects -- electron diffraction -- elemental semiconductors -- II VI semiconductors -- nanostructured materials -- particle size -- silicon -- transmission electron microscopy -- zinc compounds -- oxidized silicon micro clusters -- ZnO matrix -- micro composites -- nano composites -- SiO sub 2 glass substrates -- sputtering -- Si content -- crystallinity -- thermal annealing -- particle size -- TEM -- TED -- high energy electron irradiation -- Si ZnO -- SiO sub 2


© EDP Sciences 1997