Premium
Effects of the Heat‐Treatment Conditions on the Crystallographic Orientation of Pb(Zr,Ti)O 3 Thin Films Prepared by Polyvinylpyrrolidone‐Assisted Sol–Gel Method
Author(s) -
Yamano Akihiro,
Kozuka Hiromitsu
Publication year - 2007
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2007.02068.x
Subject(s) - materials science , mullite , substrate (aquarium) , crystallization , sol gel , thin film , layer (electronics) , polyvinylpyrrolidone , analytical chemistry (journal) , composite material , chemical engineering , mineralogy , crystallography , chemistry , nanotechnology , ceramic , organic chemistry , polymer chemistry , oceanography , engineering , geology
The effects of heat‐treatment conditions on crystallographic orientation was studied on single layer, 0.14–0.19‐μm‐thick Pb(Zr 0.53 Ti 0.47 )O 3 (PZT) films deposited on Pt(111)/TiO 2 /SiO 2 /Si(100) substrates by spin‐coating using a Pb(NO 3 ) 2 –Zr(OC 3 H 7 n ) 4 –Ti(OC 3 H 7 i ) 4 —polyvinylpyrrolidone (PVP)–CH 3 COCH 2 COCH 3 –CH 3 OC 2 H 4 OH– n ‐CH 3 OH solution. The gel films were fired either by placing the coated substrates on an alumina boat and inserting them into an electric furnace of 500°–900°C, or by placing them on a hot mullite plate of 500°–900°C so that the rear side of the substrate was in contact with the hot plate. When the samples were heated by placing on a hot mullite plate, (001)/(100) orientation of PZT occurred even at firing temperatures as low as 600°C, and the films were more completely oriented than those heated by inserting in a furnace along with an alumina boat. This suggests that either the higher heating rates or the heating from the substrate side would promote the oriented crystallization. However, when the gel films were heated up in a near‐infrared (IR) image furnace, preferential (001)/(100) orientation was observed even at low heating rates. The Si(100) substrates generate heat in the image furnace, allowing the gel films to be heated from the substrate side, which was suggested by the fact that the films do not absorb the near‐IR light while the substrate does. Therefore it can be concluded that heating the gel films from the substrate side is effective for the orientation of the films, by which orientation is realized even in PZT films derived from PVP‐containing alkoxide solutions.