Kinetically-controlled thin-film growth of layered $β$- and $γ-$Na$_{x}$CoO$_{2}$ cobaltate

J. Y. Son; Bog G. Kim; J. H. Cho

doi:10.1063/1.1943498

paper

Kinetically-controlled thin-film growth of layered $β$ - and $γ -$ Na $_{x}$ CoO $_{2}$ cobaltate

arXiv:cond-mat/0505269 · doi:10.1063/1.1943498

Abstract

We report growth characteristics of epitaxial $β$ -Na $_{0.6}$ CoO $_{2}$ and $γ$ -Na $_{0.7}$ CoO $_{2}$ thin films on (001) sapphire substrates grown by pulsed-laser deposition. Reduction of deposition rate could change structure of Na $_{x}$ CoO $_{2}$ thin film from $β$ -phase with island growth mode to $γ$ -phase with layer-by-layer growth mode. The $γ$ -Na $_{0.7}$ CoO $_{2}$ thin film exhibits spiral surface growth with multiterraced islands and highly crystallized texture compared to that of the $β$ -Na $_{0.6}$ CoO $_{2}$ thin film. This heterogeneous epitaxial film growth can give opportunity of strain effect of physical properties and growth dynamics of Na $_{x}$ CoO $_{2}$ as well as subtle nature of structural change.

accepted for publication in Applied Physics Letters

Kinetically-controlled thin-film growth of layered β- and γ−Nax​CoO2​ cobaltate

Abstract

Kinetically-controlled thin-film growth of layered $β$ - and $γ -$ Na $_{x}$ CoO $_{2}$ cobaltate