Photoluminescence Investigation of Pb(Zr,Ti)O3 Thin Films

1991 ◽  
Vol 243 ◽  
Author(s):  
Peter Zurcher ◽  
Raymond P. Jones ◽  
Yongchen Sun ◽  
R.L. Cone

AbstractPhotoluminescence (PL) excited at 1.7K with a N2-Laser (3.679eV) was used to investigate defect related electron-hole recombination transitions in ferroelectric PZT thin films. The interaction of doping, heat treatment, and hydrogen with the defect related PL spectrum has been studied. Donor/acceptor related transitions between 3.0 and 3.5eV and deep trap transitions between 2.0 and 2.6eV have been found. Certain heat treatments produce high densities of deep trap transitions in Pb(Zr0.48Ti0.52)03 thin films but not in 6% La doped PZT; different treatments are neccessary to produce similar deep trap transitions in the doped films. Hydrogen anneals eliminate the strongest deep trap transition at 2.15eV in both undoped and La-doped PZT films; however the donor/acceptor transitions are affected differently. Correlation with electrical properties seems to indicate the expected result: smaller defect densities are associated with better electrical performance.

1999 ◽  
Vol 596 ◽  
Author(s):  
W. Biegel ◽  
R. Klarmann ◽  
M. Kuhn ◽  
B. Wörz ◽  
B. Stritzker

AbstractPulsed Laser Deposition (PLD) was used to deposit La-doped Pb(Zr,Ti)O3 (PZT) thin films onto NiTi foils. The substrate alloy with composition Ni50Ti50 shows a strong shape memory effect with a transition temperature of about 80°C. This simple bicomponental system could have the potential of an actuator device (NiTi shows a strain up to 5 % during thermal cycling) with an inherent sensorial component (PZT) for the generated elongation. The deposited ceramic films were characterized with respect to their structural properties (XRD) and their ferroelectric behavior (P-E hysteresis). Under certain deposition conditions the growth of pure perovskite PZT on the polycrystalline shape memory alloy was observed. The growth morphology of PZT on NiTi was compared to the one of PZT on single crystalline substrates whereas no distinctive texture of the films on NiTi could be found. The ferroelectric behavior of the PZT films depend on the stage of bending of the film-substrate compound.


1991 ◽  
Vol 243 ◽  
Author(s):  
D. Dimos ◽  
R.W. Schwartz

AbstractThe photocurrent responses, photo-induced changes in hysteresis behavior, and electrooptic (birefringence) effects of sol-gel derived PZT films have been characterized as part of an effort to evaluate ferroelectric films for image storage and processing applications.


1996 ◽  
Vol 433 ◽  
Author(s):  
Hiromitsu Kurogi ◽  
Yukihiko Yamagata ◽  
Tomoaki Ikegami ◽  
Kenji Ebihara ◽  
Bok Yin Tong

AbstractPb(ZrxTi1−x)O3(PZT) thin films have excellent ferroelectric, optical, piezoelectric and pyroelectric properties. We prepared PZT thin films using the excimer laser ablation technique. A pulsed KrF excimer laser was used to ablate PZT bulk targets. We have studied optimum preparation conditions such as an oxygen pressure, a laser energy fluence and a substrate temperature.In this paper, we investigated the composition, crystallization and ferroelectric properties of the PZT films prepared under various deposition conditions.The X-ray diffraction (XRD) patterns showed that the PZT films prepared on MgO(100) substrates at 600°C and with a laser fluence of 2J/cm2 had a perovskite - pyrochlore mixed structure. The condition of 100 mTorr oxygen pressure provided high quality perovskite films. It is found that the stoichiometric composition of the deposited films is obtained in ambient oxygen of 100˜400 mTorr. The ferroelectric properties of the Pt/PZT/Pt/MgO structure were studied. The capacitance-voltage characteristics and the corresponding hysteresis loop of the dielectric-electric field curve were discussed.We also studied optical emission of the PZT plasma plume to understand quantitative relation between the PZT film quality and the ablation plume plasma. We identified spectral lines originated in Pb, Pb+, Zr, Zr+, Ti, Ti+, PbO and TiO. These spectral intensities have remarkable dependence on the ambient O2 pressure.


1998 ◽  
Vol 541 ◽  
Author(s):  
H. Fujisawa ◽  
S. Nakashima ◽  
M. Shimizu ◽  
H. Niu

AbstractThe grain size of MOCVD-Pb(Zr,Ti)O3 (PZT) thin films was successfully controlled by changing the grain size of Ir bottom electrodes and by changing the growth rate of PZT films. In Ir/PZT/Ir/SiO2/Si capacitors, the grain size of PZT thin films increased from 120 to 240nm as the grain size of bottom Ir electrodes increased from 50 to 200nm. The dielectric constants of PZT thin films increased from 760 to 1440 as the grain size increased from 120 to 240nm. Remanent polarization increased and coercive field decreased as the grain size increased. This dependence of electrical properties on the grain size coincided with that of ceramics.


2012 ◽  
Vol 1397 ◽  
Author(s):  
Dirk Kaden ◽  
Hans-Joachim Quenzer ◽  
Martin Kratzer ◽  
Lorenzo Castaldi ◽  
Bernhard Wagner ◽  
...  

ABSTRACTIn this work high quality ferroelectric PZT films have been prepared in-situ by hot RF magnetron sputtering. 200 mm wafer were coated with PZT films of 1 μm and 2 μm thickness at sputter rates of 45 nm/min in a high volume production sputtering tool. The films were grown on oxidized Si substrates prepared either with sputtered Ti/TiO2/Pt, sputtered Ti/TiO2/Pt/TiO2 or evaporated Ti/Pt bottom electrodes at substrate holder temperatures in the range from 550 °C to 700 °C. At these temperatures, the material nucleates in the requisite piezoelectric perovskite phase without need of an additional post annealing treatment.The films were investigated with respect to their chemical composition and their crystallographic, piezoelectric and dielectric properties. At an intermediate chuck temperature of 600 °C the PZT thin films were characterized by a minimum volume fraction of secondary nonpiezoelectric phases. A Zr/(Zr+Ti) ratio of 0.53 has been achieved matching the morphotropic phase boundary. By improving the deposition process and poling procedure, a notable high e31,f coefficient of -17.3 C/m2 has been obtained. The corresponding longitudinal piezoelectric constant was determined to have an effective longitudinal piezoelectric coefficient d33,f of 160 pm/V.


2005 ◽  
Vol 902 ◽  
Author(s):  
Serhiy Matichyn ◽  
Marco Lisker ◽  
Edmund P. Burte

AbstractIn this study lead zirkonat titanate (PZT) thin films were deposited using direct liquid injection metal organic chemical vapor deposition (DLI-MOCVD).The chemical states and the stoichiometry of PZT-films were characterized using X-ray photoelectron spectroscopy (XPS). The crystal structure of the films was investigated by X-ray diffraction (XRD).The surface composition of the films was Pb : Zr : Ti = 1.05 : 0.52 : 0.48, which indicates that the deposited films had a stoichiometric PZT composition. 130 nm thick PZT films deposited on Ir showed <110> preferred orientation.The main role for formation of the perovsktive PZT films plays the content of the lead in the deposited films. Lead deficiency causes the formation of the pyrochlore phase with poor electrical properties. In films with a significant excess of lead a second PbO phase appeared that can be observed even with naked eyes. Negligible excess of lead can be reduced by post-deposition annealing at 500-600 °C.The Ir/PZT/Ir capacitor showed large values of the remanent polarisation of about 60μC/cm2 at an applied voltage of 3 V. So high value of the remanent polarisation can be induced by structural stress in the films. After ten switch impulses the values of the remanent polarisation have significantly decreased. This is probably due to a relaxation of crystal cells.


1991 ◽  
Vol 243 ◽  
Author(s):  
Chien H. Peng ◽  
Jhing-Fang Chang ◽  
Seshu B. Desu

AbstractOptical properties were investigated for undoped, La-doped, and Nd-doped Pb(ZrxTi1-x)O3 thin films deposited on sapphire substrates by metalorganic decomposition (MOD) process. Refractive index and extinction coefficient of these films were calculated from transmission spectra in the wavelength range of 300 to 2000 nm. The packing densities of these films were calculated from the refractive index data by using the effective medium approximation. Band gap energies of these films were also reported under the assumption of direct band-to-band transition. The refractive index and band gap energy of PZT films showed a linear dependence on Zr/Ti ratio. The refractive index decreased, while the band gap energy increased with increasing zirconium content. It was also found that both La-doped and Nd-doped PZT films had higher refractive indices than those of undoped PZT films with the same Zr/Ti ratio (50/50).


2007 ◽  
Vol 14 (02) ◽  
pp. 229-234
Author(s):  
SARAWUT THOUNTOM ◽  
MANOCH NAKSATA ◽  
KENNETH MACKENZIE ◽  
TAWEE TUNKASIRI

Lead zirconate titanate (PZT) films with compositions near the morphotropic phase boundary were fabricated on Pt (111)/ Ti / SiO 2/ Si (100) using the triol sol–gel method. The effect of the pre-heating temperature on the phase transformations, microstructures, electrical properties, and ferroelectric properties of the PZT thin films was investigated. Randomly oriented PZT thin films pre-heated at 400°C for 10 min and annealed at 600°C for 30 min showed well-defined ferroelectric hysteresis loops with a remnant polarization of 26.57 μC/cm2 and a coercive field of 115.42 kV/cm. The dielectric constant and dielectric loss of the PZT films were 621 and 0.0395, respectively. The microstructures of the thin films are dense, crack-free, and homogeneous with fine grains about 15–20 nm in size.


2007 ◽  
Vol 555 ◽  
pp. 315-320 ◽  
Author(s):  
Z. Branković ◽  
G. Branković ◽  
K. Vojisavljević ◽  
M. Počuča ◽  
Tatjana Srećković ◽  
...  

The modified polymeric precursor method (Pechini method) was successfully used for the preparation of epitaxial and polycrystalline ferroelectric Pb(Zr0.52Ti0.48)O3 (PZT) thin films. Films were deposited on LaNiO3 (LNO) – coated silicium (1 0 0) and platinum substrates (Pt (1 1 1)/Ti/SiO2/Si) by spin coating technique. LNO electrodes were also prepared by the Pechini method and treated under different thermal treatment conditions to obtain films with different structural and microstructural properties. Investigation of PZT microstructure was performed as a function of orientation and morphology of the bottom electrode, as well as of thermal treatment conditions. Grain size and morphology were analyzed by AFM, while the quality and orientation of PZT films were determined by GIXRD analysis. It has been found that the proposed thermal treatment on a hot plate, with slow heating rate and long annealing time, can result in the formation of epitaxial PZT films on Si and LNO-coated Si substrates.


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