• The Korean Journal of Ceramics
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• v.1 no.1
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• pp.13-20
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• 1995

Effects of thermal annealing on the dielectric/piezoelectric properties of $Pb(Zn, Mg)_{1/3}Nb_{2/3}O_3-PbTiO_3$ ceramics (PZMNPT) with Zn/Mg=6/4) were examined across the rhombohedral/tetragonal morphotropic phase boundary (MPB). Both the relative dielectric permittivity ($\varepsilon$r)and the piezoelectric constant($d_33$)/electromechanical coupling constant ($k_p$)were increased by thermal annealing ($800^{\circ}$~$900^{\circ}C$) after sintering at $1150^{\circ}C$ for 1 hr. Based on the dielectric analysis using the series mixing model and the concept of a random distribution of the local Curie points, the observed improvements in the dielectric and piezoelectric properties of PZMN-PT were interpreted in terms of the elimination of PbO-rich amorphous intergranular layers(~1nm) induced by thermal annealing. A concrete evidence of the presence of amorphous grain-boundary layers in the unannealed (as-sintered) specimen was obtained by examining the structure of intergranular region using a TEM.

• Transactions on Electrical and Electronic Materials
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• v.5 no.2
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• pp.66-70
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• 2004

The Sr$\_$0.7/Bi$\_$2.3/Ta$_2$O$\_$9/(SBT)thin films are deposited on Pt-coated electrode (Pt/TiO$_2$/SiO$_2$/Si) using a RE magnetron sputtering method. The ferroelectric properties of SBT capacitors with annealing times were studied. As a result of conducting the X-ray diffraction analysis and the electron microscopy analysis, the perovskite phase began to grow from 10 minutes after annealing the specimen, and excellent crystallization was accomplished at 60 minutes after annealing the specimen. The remanet polarization (2P$\_$r/) value and the coercive electric field (E$\_$c/) of the SBT thin film specimen showed the most excellent characteristics at 60 minutes after annealing the specimen, which were approximately 12.40 C/$\textrm{cm}^2$ and 30 kV/cm, respectively. The leakage current density of the SBT thin film specimen as annealed for 60 minutes was approximately 2.81${\times}$10$\^$－9/A/$\textrm{cm}^2$.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.116-117
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• 2007

The $V_2O_5$ thin films deposited on Pt/Ti/$SiO_2$/Si substrates by RF sputtering method exhibited fairly good TCR and dielectric properties. It was found that film crystallinity, dielectric properties, and TCR properties were strongly dependent upon the annealing temperature. The dielectric constants of the $V_2O_5$ thin films annealed at $300^{\circ}C$ were 37.7, with a dielectric loss of 2.535, respectively. Also, the TCR values of the $V_2O_5$ thin films annealed at $300^{\circ}C$ were about -2.65%/K.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.624-627
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• 2003

The BLT thin-films were one of the promising ferroelectric materials with a good leakage current and degradation behavior on Pt electrode. The BLT target was sintered at $1100^{\circ}C$ for 4 hours at the air ambient. $Bi_{3.25}La_{0.75}Ti_3O_{12}$ (BLT) thin-film deposited on $Pt/Ti/SIO_2/Si$ wafer by rf magnetron sputtering method. At annealed $700^{\circ}C$, (117) and (006) peaks appeared the high intensity. The hysteresis loop of the BLT thin films showed that the remanent polarization ($2Pr=Pr^+-Pr^-$) was $16uC/cm^2$ and leakage current density was $1.8{\times}10^{-9}A/cm^2$ at 50 kV/cm with coersive electric field when BLT thin-films were annealed at $700^{\circ}C$. Also, the thin film showed fatigue property at least up to $10^{10}$ switching bipolar pulse cycles under 7 V. Therefore, we induce access to optimum fabrication condition of memory device application by rf-magnetron sputtering method in this report.

• Bulletin of the Korean Chemical Society
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• v.17 no.7
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• pp.637-642
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• 1996

Preparation and properties of potential CVD (Chemical Vapor Deposition) precursors for the TiO2, a major component of the perovskite materials such as PT, PLT, PZT, and PLZT were investigated. Reactions between β-diketones and TiMe3, formed in situ failed to produce stable Ti(β-diketonate)3 complexes but a stable purple solid, characterized as (OTi(BPP)2)2 (BPP=1,3-biphenyl-1,3-propanedione) was obtained when BPP was used. Several new Ti(Oi-Pr)2(β-diketonate)2 complexes with aromatic or ring substituents were synthesized by the substitution reaction of Ti(OiPr)4by β-diketones and characterized with 1H NMR, IR, ICP, and TGA. Solid complexes such as Ti(Oi-Pr)2(BAC)2 (BAC=1.-phenyl-2,4-pentanedione), Ti(Oi-Pr)2(BPP)2, Ti(Oi-Pr)2(1-HAN)2 (1-HAN=2-hydroxy-1-acetonaphthone), Ti(Oi-Pr)2(2-HAN)2 (2-HAN=1-hydroxy-2-acetonaphthone), Ti(Oi-Pr)2(ACCP)2 (ACCP=2-acetylcyclopentanone), and Ti(Oi-Pr)2(HBP)2 (HBP=2-hydroxybenzophenone) were found to be stable toward moisture and air. Ti(Oi-Pr)2(ACCP)2 and Ti(Oi-Pr)2(HBP)2 were proved to have lower melting points and higher decomposition temperatures. However, these complexes are thermally stable and pyrolysis under an inert atmosphere resulted in incomplete decomposition. Ti(Oi-Pr)2(DPM)2 (DPM=dipivaloylmethane) and Ti(Oi-Pr)2(HFAA)2 (HFAA=hexafluoroacetylacetone) were sublimed substantially during the thermal decomposition. Pyrolysis mechanism of these complexes are dependent on type of β-diketone but removal of Oi-Pr ligands occurs before the decomposition of β-diketonate ligands.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1723-1725
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• 1999

This paper is the study for piezoelectric properties of PMN-PT-PZ composition for high power piezoelectric device. It needs the properties such as high mechanical quality factor(Qm), high electromechanical coupling coefficient(kp) and high dielectric strain constant$(d_31)$, and the stable electromechanical properties under high vibration level. For acquiring this results, the value of x is changed in 0.1Pb$(Mn_{1/3}Nb_{2/3})O_3$+(0.9-x)$PbZrO_3+xPbTiO_3$ composition to find MPB(morphotropic phase boundary), and the piezoelectric constants is measured by resonance-antiresonance frequency method, based on IRE Standard. Also, it is measured as a function of the amount of additive, $Nb_2O_5$. When the composition is applied to high power device, the electromechanical properties is measured by laser vibrometer to confirm the reliablity under high vibration level. From these results, PMN-PT-PZ composition is shown excellent properties and capacity of application to high power device.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.91-96
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• 2020

The 33-mode dielectric and piezoelectric properties of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 piezoelectric single crystals were measured under large electric field and compressive stress. The phase transition from the low temperature rhombohedral to the high temperature tetragonal structure was observed in the range of 110~140℃, and the Curie temperature changing to the cubic structure was about 165℃. The polarization change according to the compressive stress and electric field was measured. Relative dielectric constant was calculated from the slope of the polarization curve applied to the electric field, and the calculated relative dielectric constant increased as the applied stress increased, and the relative dielectric constant decreased as the applied electric field increased. The strain according to the compressive stress and electric field change was measured, the piezoelectric constant was calculated from the slope of the curve, and the phase transition according to the application of pressure was confirmed. In the case of practical application as an underwater or medical ultrasonic actuator, it is necessary to properly design the magnitude of the compressive stress applied to the device and the DC bias in order to maintain linear driving.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.341-344
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• 1999

The effects of post annealing treatments of ferroelectrlclty in PZT(P $b_{1.05}$(Z $r_{0.52}$, $Ti_{0.48}$) $O_3$ thin film deposited on Pt/ $SiO_2$/Si substrate by RF-Magnetron sputtering methode was Investigated. Analyses by RTA(Rapid Thermal Annealing) treatments reveled that the crystallization process strongly depend on the healing temperature. The Perovskite structure with strong PZT (101) plan was obtained by RTA treatments at 75$0^{\circ}C$ With increasing RTA temperature of PZI thin films, the coercive field and remanent Polarization decreased, while saturation polarization( $P_{r}$) was decreased. P-E curves of Pt/PZT/Pt capacitor structures demonstrate typical hysteresiss loops. The measure values of $P_{r}$,. $E_{c}$ and dielectric constants by post annealed at 75$0^{\circ}C$ were 38 $\mu$C/$\textrm{cm}^2$ 35KV/cm and 974, respectively. Switching polarization versus fatigue characteristic showed 12% degradation up to 10$^{7}$ cycles.s.s.s.s.s.s.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05b
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• pp.42-45
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• 2001

The high permittivity are applied to DRAM and FRAM. (Ba,Sr)$TiO_3$ (EST) thin films were prepared by Sol-Gel method. BST solution was made and spin-coated on $Pt/SiO_2/Si$ substrate at 4000 [rpm] for 10 seconds in a time coating. Coated specimens were dried at $90[^{\circ}C]$ for 5 minutes. Coating process was repeated from 3 times to 5 times and then sintered at $750[^{\circ}C]$ for 30 minutes. Each specimen was analyzed structure and electrical characteristics. Thickness of BST ceramics thin films are about 2600-2800[$\AA$] in 3 times. Dielectric constant of thin films was little decreased at 1[KHz]~1[MHz]. Dielectric constant and loss to frequency were 250 and 0.02 in BST3. The property of leakage current was stable When the applied voltage was 0~3[V] Leakage current was $10^{9}\sim10^{11}$[A] at 0~3[V].

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.3
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• pp.207-213
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• 2003

The Sr$\_$0.7/Bi$\_$2.6/Ta$_2$O$\_$9/(SBT) thin films are deposited on Pt-coated electrode(Pt/TiO$_2$/SiO$_2$/Si) using RF magnetron sputtering method. The structural and electrical properties of SBT capacitors were influenced with annealing atmosphere. In the XRD pattern, the SBT thin films in all annealed atmosphere had (105) orientation. In the SEM images, Bi-layered perovskite phase was crystallized in all annealing atmosphere and grain largely grew in oxygen annealing atmosphere. The maximum remnant polarization and the coercive electric field in oxygen annealing atmosphere are 12.40[${\mu}$C/cm$^2$] and 30[kV/cm] respectively. The dielectric constant and leakage current density of capacitors annealed oxygen atmosphere are 340 and 2.13${\times}$10$\^$-9/ [A/cm$^2$] respectively. The fatigue characteristics of SBT capacitors did not change up to 10$\^$10/ switching cycles.