Journal of the Ceramic Society of Japan
Online ISSN : 1348-6535
Print ISSN : 1882-0743
ISSN-L : 1348-6535
Feature: Cutting edge research on electroceramics 2018: Full papers
Low-temperature deposition of Li substituted (K,Na)NbO3 films by a hydrothermal method and their structural and ferroelectric properties
Takahisa SHIRAISHIYuta MUTOYoshiharu ITOAkinori TATEYAMAHiroshi UCHIDATakanori KIGUCHIMinoru K. KUROSAWAHiroshi FUNAKUBOToyohiko. J. KONNO
ジャーナル フリー

2019 年 127 巻 6 号 p. 388-393


Li substituted (K,Na)NbO3 films with K-rich composition against polymorphic phase boundary were deposited at 240°C on (100)La:SrTiO3 substrates by hydrothermal method. The amount of Li content in films was controlled by changing the nominal composition of raw materials, A = [LiOH]/([KOH] + [NaOH] + [LiOH]). X-ray diffraction measurement showed that {001}c-oriented epitaxial (K,Na,Li)NbO3 films were obtained for all nominal compositions (A = 0–0.1). However, the diffraction peaks originated from a secondary phase were also detected in the range of A = 0.05–0.1. Plan-view scanning electron microscopy observation revealed that (K,Na,Li)NbO3 films possessed square-shape feature in accordance with the epitaxial relationship between film and substrate, while the secondary phase exhibited triangular- and pyramid-shaped features. The distribution of the elements across the thickness was investigated by time-of-flight secondary ion mass spectrometry. Transmission electron microscopy revealed the columnar structure of the film. In addition, nanoscale-pores have been found to exist in the boundary of each column by scanning transmission electron microscopy. (K,Na,Li)NbO3 films, A up to 0.03, showed ferroelectricity, and the maximum remanent polarization was observed at A = 0.01.

© 2019 The Ceramic Society of Japan
前の記事 次の記事