Electron Microscopy Observation of TiO2 Nanocrystal Evolution in High-Temperature Atomic Layer Deposition

Published

October 4, 2013

Author(s)

Albert Davydov, Jian Shi, Alexander Kvit, Sergiy Krylyuk, Xudong Wang

Abstract

Understanding the evolution of amorphous and crystalline phases during atomic layer deposition (ALD) is essential for creating high quality dielectrics, multifunctional films/coatings, and predictable surface functionalization. Through comprehensive atomistic electron microscopy study of ALD TiO2 nanostructures at designed growth cycles, we revealed the transformation process and sequence of atom arrangement during TiO2 ALD growth. Evolution of TiO2 nanostructures in ALD was found following a path from amorphous layers to amorphous particles to metastable crystallites and ultimately to stable crystalline forms. Such a phase evolution is a manifestation of the Ostwald-Lussac Law, which governs the advent sequence and amount ratio of different phases in high-temperature TiO2 ALD nanostructures. The amorphous-crystalline mixture also enables a unique anisotropic crystal growth behavior at high temperature forming TiO2 nanorods via the principle of vapor-phase oriented attachment.

Citation

Nano Letters

Volume

13

Pub Type

Journals

Keywords

atomic layer deposition, oriented attachment, Ostwald-Lussac law, TiO2

Citation

Davydov, A. , Shi, J. , Kvit, A. , Krylyuk, S. and Wang, X. (2013), Electron Microscopy Observation of TiO2 Nanocrystal Evolution in High-Temperature Atomic Layer Deposition, Nano Letters (Accessed May 19, 2024)