Additive controlled crystallization of barium titanate powders and their application for thin-film ceramic production: Part II. From nano-sized powders to ceramic thin films

2001 ◽  
Vol 16 (7) ◽  
pp. 1911-1915 ◽  
Author(s):  
B. Grohe ◽  
G. Miehe ◽  
G. Wegner

Nano-sized barium titanate (BaTiO3) particles prepared by the sol-to-precipitate method in aqueous/organic medium served to obtain thin-layer ceramic films of the tetragonal electroactive phase. Poly(methacrylic acid) works efficiently to process the suspensions and to obtain green films. Sintering the green films under O2–Ar atmosphere gave thin-layered ceramics of a thickness of 0.5–1.0 mm with a dielectric constant of 3750 at 20 °C (1 kHz).

2001 ◽  
Vol 16 (7) ◽  
pp. 1901-1910 ◽  
Author(s):  
B. Grohe ◽  
G. Miehe ◽  
G. Wegner

Stoichiometric barium titanate (BaTiO3) was synthesized in aqueous solution with acetone and/or methanol as additives to control the crystallization process. Adjusted nano-sized particles and narrow particle size distributions were achieved at 60 °C with additive concentrations up to 243 ml/ l. The growth kinetics showed that the additives influence the nucleation of the BaTiO3 particles and tend to suppress Ostwald ripening.


2005 ◽  
Vol 475-479 ◽  
pp. 1587-1590
Author(s):  
Bo Ping Zhang ◽  
Jing Feng Li ◽  
Yan Dong ◽  
Takashi Iijima

A series of Pb(Ti1-xAlx)O3, Pb(Ti1-xNbx)O3 and Pb(Ti1-xAlx/2Nbx/2)O3 thin films were fabricated onto Pt/Ti/SiO2/Si(100) substrates using a chemical solution deposition process. The dielectric constant of the Pb(Ti1-xAlx)O3 thin films increased with increase of aluminum content, while a maximum dielectric constant value was observed for the Pb(Ti1-xNbx)O3 and Pb(Ti1 xAlx/2Nbx/2)O3 thin films when the doping contents were 10 and 20 mol%, respectively. The dielectric constant of the Pb(Ti0.8Al0.1Nb0.1)O3 thin film is about 600, being two times higher than those of Pb(Ti0.9Al0.1)O3 and Pb(Ti0.9Nb0.1)O3 thin films. The Pb(Ti0.8Al0.1Nb0.1)O3 thin film showed less than 10-7 A/cm2 current density at ±150 kV/cm, being superior to the leakage property of the PbTiO3, Pb(Ti0.9Al0.1)O3 and Pb(Ti0.9Nb0.1)O3 thin films. The co-doping of aluminum and niobium is more effective to increase the dielectric and ferroelectric properties as compared with the individual aluminum or niobium doping.


Author(s):  
D.W. Susnitzky ◽  
S.R. Summerfelt ◽  
C.B. Carter

Solid-state reactions have traditionally been studied in the form of diffusion couples. This ‘bulk’ approach has been modified, for the specific case of the reaction between NiO and Al2O3, by growing NiAl2O4 (spinel) from electron-transparent Al2O3 TEM foils which had been exposed to NiO vapor at 1415°C. This latter ‘thin-film’ approach has been used to characterize the initial stage of spinel formation and to produce clean phase boundaries since further TEM preparation is not required after the reaction is completed. The present study demonstrates that chemical-vapor deposition (CVD) can be used to deposit NiO particles, with controlled size and spatial distributions, onto Al2O3 TEM specimens. Chemical reactions do not occur during the deposition process, since CVD is a relatively low-temperature technique, and thus the NiO-Al2O3 interface can be characterized. Moreover, a series of annealing treatments can be performed on the same sample which allows both Ni0-NiAl2O4 and NiAl2O4-Al2O3 interfaces to be characterized and which therefore makes this technique amenable to kinetics studies of thin-film reactions.


2019 ◽  
Vol 6 (10) ◽  
pp. 106321 ◽  
Author(s):  
Alireza Kashir ◽  
Hyeon-Woo Jeong ◽  
Woochan Jung ◽  
Yoon Hee Jeong ◽  
Gil-Ho Lee

2003 ◽  
Vol 766 ◽  
Author(s):  
Jin-Heong Yim ◽  
Jung-Bae Kim ◽  
Hyun-Dam Jeong ◽  
Yi-Yeoul Lyu ◽  
Sang Kook Mah ◽  
...  

AbstractPorous low dielectric films containing nano pores (∼20Å) with low dielectric constant (<2.2), have been prepared by using various kinds of cyclodextrin derivatives as porogenic materials. The pore structure such as pore size and interconnectivity can be controlled by changing functional groups of the cyclodextrin derivatives. We found that mechanical properties of porous low-k thin film prepared with mCSSQ (modified cyclic silsesquioxane) precursor and cyclodextrin derivatives were correlated with the pore interconnection length. The longer the interconnection length of nanopores in the thin film, the worse the mechanical properties of the thin film (such as hardness and modulus) even though the pore diameter of the films were microporous (∼2nm).


Sign in / Sign up

Export Citation Format

Share Document