Preparation of HfO₂–Al₂O₃ nanocomposite films using chemical vapor deposition

Abstract

We prepared HfO₂–Al₂O₃ nanocomposite films using chemical vapor deposition. Fibrous and lamellar microstructures formed in the monoclinic and tetragonal HfO₂ (m/t-HfO₂)–α-Al₂O₃ films at deposition temperature of 1573 K and Al mole fraction in the precursor vapor of 36–74 mol %Al₂O₃. Characterization by electron microscopy revealed that the m/t-HfO₂ fibrous and lamellar structures are present throughout the α-Al₂O₃ columnar matrix above 50 mol %Al₂O₃ (55 vol %Al₂O₃), while α-Al₂O₃ lamellar structure was formed in m-HfO₂ matrix below 50 mol %Al₂O₃.