Effective Orientation Control of Pb(Zr0.4Ti0.6)O3 Thin Films Using A New Ti/Pb(Zr0.4Ti0.6)O3 Seeding Layer

2003 ◽  
Vol 784 ◽  
Author(s):  
B. K. Moon ◽  
O. Arisumi ◽  
K. Hornik ◽  
R. Bruchhaus ◽  
H. Itokawa ◽  
...  
Keyword(s):  
Seed Layer ◽  
Perovskite Phase ◽  
Pyrochlore Phase ◽  
Total Thickness ◽  
Seeding Layer ◽  
Pzt Film ◽  
Peak Intensity ◽  
Polarization Saturation ◽  
Intensity Ratios ◽  
Seed Layers

ABSTRACTThe effect of thin Ti/PbZr0.4Ti0.6O3 seed layers on the properties of PbZr0.4Ti0.6O3 (PZT) capacitors has been investigated. The seed layer is based on a bi-layer of thin Ti and thin PZT with a total thickness ranging from 10 to 25 nm, which was deposited on Ir/Pt or Ir/IrO2/Pt by sputtering. After crystallization of the seed layers the main 130-nm-thick PZT film was deposited and crystallized. As a result, a highly preferred (111)-orientation of the PZT was obtained on a 10-nm-thick seed layer, where the peak intensity ratios of (111)/{100} and (111)/{110} are about 100 and 20, respectively. The 10-nm-thick seed forms a pyrochlore phase with a very smooth surface, where the formation of the pyrochlore phase is attributed to Pb diffusion, resulting in a Pb deficient stoichiometry. The seed layer transformed to the perovskite phase during the main PZT crystallization. It is shown that an IrO2 layer beneath the Pt can prevent Pt layer degradation related to the volume expansion due to the oxidation of Ir during the main PZT crystallization. Capacitors with the 10-nm-thick seed layer fabricated on the Ir/Pt and Ir/IrO2/Pt substrates showed typical 2 Pr values of 44.0 μC/cm2 and 41.2 μC/cm2, respectively. The voltage found for 90%-polarization saturation is about 3.0 V, and the capacitors are fatigue-free at least up to 1010 switching cycles.

Role of SrTiO3 Seed Layer on Low-temperature Crystallization of Pb(Zr, Ti)O3 Films Prepared by Metalorganic Chemical Vapor Deposition

2007 ◽  
Vol 1034 ◽  
Author(s):  
Ji-Won Moon ◽  
Naoki Wakiya ◽  
Takanori Kiguchi ◽  
Tomohiko Yoshioka ◽  
Tanaka Junzo ◽  
...  
Keyword(s):  
Low Temperature ◽  
Seed Layer ◽  
Chemical Vapor ◽  
Pzt Film ◽  
Pzt Films ◽  
Low Temperature Crystallization ◽  
Seed Layer Thickness ◽  
Temperature Crystallization ◽  
Seed Layers

AbstractRole of SrTiO3 seed layer on low-temperature crystallization of Pb(Zr, Ti)O3 (PZT) film was investigated. The SrTiO3 seeds were prepared by pulsed laser deposition (PLD) with the temperature range of 400-600 °C and PZT films were prepared by thermal MOCVD. The pyrochlore free PZT films can be successfully crystallized at around 340 °C on SrTiO3 seed layers by thermal MOCVD. It was found that the role of SrTiO3 seed layer is not only pyrochlore suppression but also perovskite promotion. It is also considered that crystallinity, surface coverage and seed layer thickness are important parameters for low-temperature crystallization and electrical properties of PZT films.

scholarly journals Integrated Polypyrrole Flexible Conductors for Biochips and MEMS Applications

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Rakefet Ofek Almog ◽  
Hadar Ben-Yoav ◽  
Yelena Sverdlov ◽  
Tsvi Shmilovich ◽  
Slava Krylov ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Aspect Ratio ◽  
Seed Layer ◽  
Conductive Polymer ◽  
Sensors And Actuators ◽  
Flexible Sensors ◽  
Planar Structures ◽  
Polymeric Substrates ◽  
Seed Layers ◽  
Structural Polymers

Integrated polypyrrole, a conductive polymer, interconnects on polymeric substrates were microfabricated for flexible sensors and actuators applications. It allows manufacturing of moving polymeric microcomponents suitable, for example, for micro-optical-electromechanical (MOEMS) systems or implanted sensors. This generic technology allows producing “all polymer” components where the polymers serve as both the structural and the actuating materials. In this paper we present two possible novel architectures that integrate polypyrrole conductors with other structural polymers: (a) polypyrrole embedded into flexible polydimethylsiloxane (PDMS) matrix forming high aspect ratio electrodes and (b) polypyrrole deposited on planar structures. Self-aligned polypyrrole electropolymerization was developed and demonstrated for conducting polymer lines on either gold or copper seed layers. The electropolymerization process, using cyclic voltammetry from an electrolyte containing the monomer, is described, as well as the devices’ characteristics. Finally, we discuss the effect of integrating conducting polymers with metal seed layer, thus enhancing the device durability and reliability.

Stabilization of perovskite phase and dielectric properties of Pb(Zn, Mg)1/3Nb2/3O3-PbTiO3 ceramics prepared by excess constituent oxides

1994 ◽  
Vol 9 (10) ◽  
pp. 2634-2644 ◽  
Author(s):  
Hyun M. Jang ◽  
Kyu-Mann Lee ◽  
Moon-Ho Lee
Keyword(s):  
Phase Transition ◽  
Diffuse Phase Transition ◽  
Short Range ◽  
Perovskite Phase ◽  
Complex Impedance ◽  
Pyrochlore Phase ◽  
Charge Carriers ◽  
Pbtio3 Ceramics ◽  
Additional Formation ◽  
Diffuse Phase

The perovskite phase in PZN-PMN-PT (PbZn1/3Nb2/3O3-PbMg1/3Nb2/3O3-PbTiO3) pseudoternary ceramics was stabilized by the addition of excess constituent divalent oxides (PbO, MgO, and ZnO). 5 mol% excess MgO or 7.5 mol% excess PbO was sufficient to eliminate the remnant cubic pyrochlore phase after sintering at 1100 °C for 1 h. The enhanced diffuse phase transition (DPT) and the decrease in the electrical resistivity were observed in the presence of excess ZnO or MgO. These were interpreted in terms of the additional formation of negatively charged, short-range ordered 1: 1 domains with a concomitant generation of charge carriers (holes). The behavior of excess MgO or ZnO at concentrations above 5 mol% was studied by examining complex impedance patterns.

Barium titanate-added lead nickel niobate ferroelectrics: Accelerated perovskite formation and dielectric properties

1996 ◽  
Vol 11 (12) ◽  
pp. 3064-3070 ◽  
Author(s):  
Chung-Hsin Lu ◽  
Jai-Fang Wu
Keyword(s):  
Frequency Dependence ◽  
Solid Solutions ◽  
Perovskite Phase ◽  
Pyrochlore Phase ◽  
Lattice Parameter ◽  
Cubic Symmetry ◽  
Dielectric Peak ◽  
Random Arrangement ◽  
Reaction Conversion ◽  
Lead Nickel

The addition of BaTiO3 to Pb(Ni1/3Nb2/3)O3 has been confirmed to vary the formation kinetics of the perovskite solid solutions of Pb(Ni1/3Nb2/3)O3-BaTiO3, and to suppress the generation of the pyrochlore phase. A semiquantitatively calculated reaction conversion verified that increasing the BaTiO3 content significantly accelerated the formation of the perovskite solid solutions. The formed solid solutions of Pb(Ni1/3Nb2/3)O3-BaTiO3 (up to 90 mol% of BaTiO3) exhibited a cubic symmetry at room temperature. The lattice parameter monotonously decreased with an increase in the BaTiO3 content. The structural stability of the perovskite phase was found to be enhanced by the addition of BaTiO3 as well. The formed solid solutions were able to maintain the perovskite structure without decomposition when heated up to 1250 °C. The frequency dependence of the apparent Curie temperature and the diffuseness of the dielectric peak of sintered specimens were increased with increasing the BaTiO3 content up to 50 mol%. Whereas with further addition, the relaxor characteristics in the specimens became obscure, associated with lower frequency dependence and less broadening of the dielectric maximum. The largest broadening of the dielectric peak occurred at x = 0.5, implying that this composition exhibited the most disordered structure, which is probably related to the most random arrangement of B-site cations in oxygen octahedran.

Thickness effect of sputtered ZnO seed layer on the fabrication of ZnO nanorods on flexible polyimide films and their ethanol gas sensing properties

2011 ◽  
Vol 1303 ◽  
Author(s):  
Hosang Ahn ◽  
Seon-Bae Kim ◽  
Dong-Joo Kim
Keyword(s):  
Seed Layer ◽  
Flexible Substrate ◽  
Zno Nanorods ◽  
Debye Length ◽  
Morphological Characteristics ◽  
Gas Absorption ◽  
Thickness Effect ◽  
Nitrate Hexahydrate ◽  
Zno Nanostructures ◽  
Seed Layers

ABSTRACTControlled ZnO nanostructures were grown on a flexible substrate for the future development of smart sensing tags. Thermolysis-assisted chemical solution deposition was used to grow ZnO nanorods at 85°C from 0.01mol of Zinc nitrate hexahydrate and HMT (Hexamethyltetramine) solution. To promote and modulate the ZnO nanorods, R.F. sputtered ZnO seed layers were deposited on polyimide substrates at various film thicknesses in the range of 8 to 160 nm. The optimum processing conditions to fabricate ZnO nanostructures have been investigated to examine the growth behaviors and to correlate the process parameters with the morphological characteristics. When the ethanol gas sensitivities were measured at different thickness of ZnO seed layers before growing ZnO nanorods, the highest sensitivity was obtained at 40 nm thick ZnO film at 300°C where the film thickness is similar to the Debye length. When ZnO nanorods were grown on such a ZnO seed layer, the sensitivities were more heavily influenced by the ZnO nanostructures rather than the thickness of the seed layer probably due to the dominant proportion of carrier density involved with the gas absorption.

An Effective Way to Suppress the Pyrochlore Phase Formation in SBT Thin Films

2003 ◽  
Vol 784 ◽  
Author(s):  
Se-Yeon Jung ◽  
Woo-Chul Kwak ◽  
Seung-Joon Hwang ◽  
Yun-Mo Sung
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Seed Layer ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Energy Difference ◽  
Ion Diffusion ◽  
Aurivillius Phase ◽  
Si Substrates ◽  
Coating Methods

ABSTRACTSr0.7Bi2.4Ta2O9 (SBT) thin films were deposited on Pt/Ti/SiO2/Si substrates with and without a seed layer of ∼40 nm thickness using sol-gel and spin coating methods. The influence of seed layer on the phase formation characteristics of SBT thin films was investigated using x-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. Formation of pyrochlore as well as Aurivillius phase was observed in both the unseeded and seeded SBT films heated at 740°C. However, it was revealed that Aurivillius phase formation was enhanced in seeded SBT thin films and pyrochlore phase formation was highly suppressed. In this study, two possible mechanisms for the suppression of pyrochlore phase formation were proposed from the perspectives of activation energy difference for Aurivillius and pyrochlore phase formation and Bi-ion diffusion to pyrochlore phase.

Crystallization of Amorphous Thin BST/MgO(001) Films Grown by R.F. Magnetron Sputtering

1997 ◽  
Vol 493 ◽  
Author(s):  
D. Y. Noh ◽  
H. H. Lee ◽  
J. H. Je ◽  
H. K. Kim
Keyword(s):  
Thick Film ◽  
Intermediate Phase ◽  
Perovskite Phase ◽  
Pyrochlore Phase ◽  
Interface Area ◽  
Crystalline Orientation ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Experiment ◽  
Film Substrate

ABSTRACTThe crystallization of amorphous BST thin films was studied in a synchrotron x-ray scattering experiment. At around 600°C, an intermediate phase, which was suspected to be a metastable pyrochlore phase, was formed. The x-ray reflectivity curves showed that the film-substrate interface became rough as the pyrochlore-like phase was formed. This suggests that the pyrochlore phase was nucleated near the interface area. Upon further annealing to higher temperatures, the film transformed to the crystalline perovskite phase. The crystallization was sensitive to the film thickness. In the thin 550Å thick film, the crystallization occurred at 750 °C with the <001> preferred orientation. On the other hand, the 5500Å thick film became crystalline even at 500°C with random crystalline orientation. The observed thickness dependence of the crystallization suggests that the crystalline perovskite phase was nucleated in the bulk of the film, rather than the near interface area.

Effect of Pb Content on the Fatigue Properties of D.C. Reactive Sputtering-Derived PZT Thin Films

2006 ◽  
Vol 326-328 ◽  
pp. 613-616
Author(s):  
Dae Jin Yang ◽  
Seong Je Cho ◽  
Jong Oh Kim ◽  
Won Youl Choi
Keyword(s):  
Lead Zirconate Titanate ◽  
Perovskite Phase ◽  
Fatigue Behavior ◽  
Ferroelectric Properties ◽  
Pyrochlore Phase ◽  
Reactive Sputtering ◽  
Lead Zirconate ◽  
Fatigue Properties ◽  
Pzt Thin Films ◽  
Pzt Films

Lead zirconate titanate (Pb(Zr0.48Ti0.52)O3 or PZT) films were grown on platinized silicon wafers (Pt/SiO2/Si) by d.c. reactive sputtering method with multi targets. The Pb content of PZT films has been widely recognized as affecting not only the phase formation and microstructure but also the dielectric and ferroelectric properties. Pb content of PZT films was controlled by the variation of Pb target current. The relation between Pb content and Pb target current was expressed as y=0.89x-11.09. The x and y are Pb target current and Pb content, respectively. The pyrochlore phase was transformed to perovskite phase as Pb content was increased. This phase transformation improved the ferroelectric properties of PZT films. In PZT films with perovskite phase, fatigue properties were not improved with excess Pb content. Fatigue properties of PZT films began to be fatigued after 106 switching cycles and coincided with the typical PZT fatigue behavior. Excess Pb content (Pb vacancy) did not affect the fatigue properties of PZT films.

Multilayer Ceramic Capacitors Based on Pb(Mg1/3Nb2/3)O3

1986 ◽  
Vol 72 ◽  
Author(s):  
O. Bouquin ◽  
M. Lejeune ◽  
J. P. Boilot
Keyword(s):  
Perovskite Phase ◽  
Slip Casting ◽  
Pyrochlore Phase ◽  
Average Concentration ◽  
Casting Method ◽  
Multilayer Ceramic Capacitors ◽  
Life Tests ◽  
Multilayer Capacitors ◽  
Multilayer Ceramic ◽  
Large Capacitance

AbstractMultilayer capacitors were made from Pb(Mg1/3Nb2/3)O3 compositon by an usual technique: ceramic green sheets formed by slip casting method, printed with an 70% wt Ag- 30% wt Pd internal electrode and sintered at temperature ranging from 950 to 11OO°C. Chip capacitors exhibit large capacitance and temperature characteristics meet Z5U specification. Electrical properties of MLC based on PMN depend on specific parameters such as the average concentration of pyrochlore phase and perovskite phase, and the homogeneity degree of dielectric layers. Load humidity life tests show a degradation of some chips which can be connected with the formation of a surface layer rich in pyrochlore phase.

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