Texture and Phase Analysis of a Ca3Co4O9 / Si (100) Thermoelectric Film

Published

July 26, 2007

Author(s)

Winnie K. Wong-Ng, Y F. Hu, Mark D. Vaudin, B He, Makoto Otani, Nathan Lowhorn, Q Li

Abstract

This paper reports the texture analysis as well as the identification of two crystalline phases between a thin film of monoclinic Ca3Co4O9 and a cubic (100) Si substrate, using a diffractometer equipped with a 2-dimensional area detector. No reflections other than 00l were observed in the symmetric configuration using a x-ray powder diffraction scan (Bragg-Brantano geometry). Pole figures collected for six reflections using asymmetric configurations did not show ab plane epitaxial relationships between the film and the substrate. These results establish the Ca3Co4O9 fiber texture of the film with the (001) pole parallel to the surface normal. Single-crystal-like second phases, CaCoSi2O6 and CoO, presumably the interface reaction products of Ca3Co4O9 with the substrate Si, were identified. The near 4-fold symmetry and the similar intensity displayed by both 220 and 400 reflections from the CaCoSi2O6 structure indicated an epitaxial relation between CaCoSi2O6 and Si with four symmetry-induced variants being generated with approximately equal volume fractions.

Citation

Journal of Applied Physics

Volume

102

Issue

3

Pub Type

Journals

Keywords

Ca₃Co₄O₉ film, CaCoSi₂O₆, CoO, fiber texture, interfacial reactions, second phases, Si substrate, thermoelectric material

Citation

Wong-Ng, W. , Hu, Y. , Vaudin, M. , He, B. , Otani, M. , Lowhorn, N. and Li, Q. (2007), Texture and Phase Analysis of a Ca₃Co₄O₉ / Si (100) Thermoelectric Film, Journal of Applied Physics (Accessed October 11, 2025)