• 한국세라믹학회지
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• 제51권6호
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• pp.623-628
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• 2014

Orthorhombic $Ba(Ti_{0.94}Zr_{0.06})O_3$ single crystals are fabricated using the cost-effective solid-state single crystal growth (SSCG) method; their dielectric and piezoelectric properties are also characterized. Measurements show that (001) $Ba(Ti_{0.94}Zr_{0.06})O_3$ single crystals have an electromechanical coupling factor ($k_{33}$) higher than 0.83, piezoelectric charge constant ($d_{33}$) of about 400 [pC/N], and piezoelectric voltage constant ($g_{33}$) higher than 50 [${\times}10^{-3}Vm/N$]. The transition temperature ($T_{OT}$) of the (001) $Ba(Ti_{0.94}Zr_{0.06})O_3$ single crystals between orthorhombic and tetragonal phases is also observed to be about $61^{\circ}C$. Because their electromechanical coupling factor ($k_{33}$) and piezoelectric voltage constant ($g_{33}$) are higher than those of soft PZT ceramics, it is expected that (001) $Ba(Ti_{0.94}Zr_{0.06})O_3$ single crystals can be used as "lead-free" piezoelectric materials in many piezoelectric applications.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 1998년도 제1회 총회 및 추계학술발표회
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• pp.60-60
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• 1998

• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.201-204
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• 2009

$BaTiO_3/SrTiO_3$ and $PbTiO_3/PbZrO_3$ superlattice thin films were fabricated on $Pt/Ti/SiO_2/Si$ substrate by the pulsed laser deposition process. The morphologies and physical properties of deposited films were characterized by using X-ray diffractometer, HR-SEM, and Impedance Analyzer. XRD data and SEM images of the films indicate that each layer was well deposited alternatively in the superlattice structure. The dielectric constant of $BaTiO_3/SrTiO_3$ superlattice thin film was higher than that of individual $BaTiO_3$ or $SrTiO_3$ film. Same result was obtained in the $PbTiO_3/PbZrO_3$system. The dielectric constant of a superlattice film was getting higher as the number of layer is increased.

• 대한전기학회논문지
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• 제41권8호
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• pp.858-868
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• 1992

0.085Ba(LaS11/2TNbS11/2T)OS13T-0.915Pb(ZrS1yTTiS11-yT)OS13T (0.45$\leq$y$\leq$0.65) transparent electrooptic ceramics were fabricated by two-stage sintering method. The structural, ferroelectric and electrooptic properties were investigated varying composition and second sintering time. Also the possibility of application to electrooptic device was studied. If we increase the PbZrOS13T contents, dielectric constants were increased and Curie temperature was decreased. In the composition of 0.55[mol] PbZrOS13T, electromechanical coupling factor and piezoelectric charge constant were the highest values of 43[%] and 173x10S0-12T[C/N], respectively. Mechanical quality factors were decreased with the increasing PbZrOS13T contents. Light transmittance was increased with wavelength when measured from 300[nm] to 900[nm], and with PbZrOS13T contents in the range of 0.50[mol]-0.65[mol], and had the highest value of 67[%] in the composition of 0.65[mol] PbZrOS13T. From the results of ferroelectric hysteresis loop and transmitted light intensity with electric field, the specimens with compositions of 0.65,0.60,0.55[mol] PbZrOS13T were applicable to electrooptic memory device and those with compositions of 0.50,0.45[mol] PbZrOS13T were applicable to linear electrooptic device.

• Nuclear Engineering and Technology
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• 제56권5호
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• pp.1822-1829
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• 2024

The search for materials that serve as good shields for radiation has become very important in light of the increasing exposure to ionizing radiation in various vital sectors. The aim is to search for novel materials with better radiation shielding properties that are stable, nontoxic, and abundant and environment friendly. The solidstate reaction approach has been used to synthesize a few ceramics, including BaZr_XTi_1-XO₃, Ba_1-XLa_XTiO₃ and Ba_1-XLa_XZr_XTi_1-XO₃ (with x = 0.10) i.eBaZr_0.10Ti_0.90O₃ (BZT), Ba_0.90La_0.10TiO₃ (BLT), and Ba_0.90La_0.10Zr_0.10Ti_0.90O₃ (BLZT). The density of the prepared samples varies from 6.3471 to 11.6003 g/cm³. The X-ray diffraction technique, shows strong peaks to confirm the crystalline structure of prepared ceramic samples. Using the G-P fitting approach, the advanced radiation shielding parameters (build-up factor) have been evaluated in the photon energy region of 1.5 keV-15 MeV. It is observed from the results that exposure buildup factor (EBF) and energy absorption buildup factor (EABF) are maximum for BLZT and has the minimum value for BZT in the entire photon energy regime. The results of this work should be useful in radiation shielding applications such as in industry, medicine, and nuclear engineering.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.301-304
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• 2002

We investigated the structural and electrical properties of Ce-doped Ba($Zr_{0.2}Ti_{0.8}$)$O_3$(BCZT) thin films with a mole fraction of x=0.2 and a thickness about 100 nm. BCZT films were prepared on Pt/Ti/$SiO_2$/Si substrate by a RF magnetron sputtering system. We have measured the thickness profile with Ar/$O_2$ ratio and the surface roughness. It was observed that the oxygen gas, which introduced during the film deposition, have an influence on the roughness of the film and the film roughness was reduced by annealing from 2.33 nm to 2.02 m (RMS at $500^{\circ}C$, Ar:6 scrim, $O_2$:6 sccm). We have found that annealing procedure after top electrode deposit can reduce the dissipation factor.

• 한국전기전자재료학회논문지
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• 제16권5호
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• pp.361-364
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• 2003

It was investigated that the structural and electrical Properties of Ce-doped Ba(Zr$_{x}$Ti$_{1-x}$ )O$_3$ (BCZT) thin films with a mole fraction of x=0.2 and a thickness about 100 nm. BCZT films were prepared on Pt/Ti/SiO$_2$/Si substrate by a RF magnetron sputtering system. We have measured the thickness profile with Ar/O$_2$ ratio and the surface roughness. It was observed that the oxygen gas, which introduced during the film deposition, have an influence on the roughness of the film and the film roughness was reduced by annealing from 2.33 nm to 2.02 nm (RMS at 500 $^{\circ}C$, Ar:6 sccm, $O_2$:6 sccm). It was found that annealing procedure after top electrode deposit can reduce the dissipation factor.

• 한국전기전자재료학회논문지
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• 제24권12호
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• pp.955-961
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• 2011

We investigated the physical properties of stoichiometric and non-stoichiometric oxide doped complex perovskite, $Ba(Zn_{1/3}Ta_{2/3})O_3$ ceramics and their impacts on the microwave dielectric performances using various characterization techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and network analyzer. According to the measurement of lattice constant changes, anomalous lattice volume contraction of $ZrO_2$ doped $Ba(Zn_{1/3}Ta_{2/3})O_3$ sample only showed the dielectric quality factor enhancements, which was due to the lattice volume contraction as well as the 1:2 B-site cation ordering. In addition, NiO doping was useful to the stabilization of temperature coefficient of resonance frequency.

• 한국세라믹학회지
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• 제51권4호
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• pp.283-288
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• 2014

PdO-doped $BaZr_{0.85}Y_{0.15}O_{3-\delta}$ (BZPY) proton conductors have been proposed as applicable for intermediate temperature electrolytes for protonic ceramic fuel cells (PCFCs) because the PdO doping is effective for improving the proton conductivity of $BaZr_{0.85}Y_{0.15}O_{3-\delta}$ (BZY) with high affinity for hydrogen. In order to further improve the conductivity of BZPY, two-phase composite electrolytes consisting of a BZPY and molten carbonate were designed. Dense BZPY-based composite electrolytes were fabricated after sintering at $670^{\circ}C$ for 4 h, since molten carbonates fill the grain boundary of the porous BZPY matrix. Furthermore, BZPY/$(Li-0.5Na)_2CO_3$ composites show a significantly enhanced protonic conductivity at intermediate temperatures. This may be because easy proton transport is possible through the interface of the carbonate and oxide phase.

• 한국초전도ㆍ저온공학회논문지
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• 제6권3호
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• pp.12-15
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• 2004

There are two major approaches to obtain texture template for HTS coated conductor (CC) ---IBAD and RABiTS. CC's with IBAD template showed both longer and higher Ic results so far. IBAD for CC began with YSZ, the processing of which is very slow compared to other processings needed for the fabrication of CC. Because of this very slow processing speed, IBAD with other materials such as Gd$_2$Zr$_2$O$_{7}$(GZO) and MgO have been developed. The processings of IBAD-GZO and IBAD-MgO are known to be up to 3times and 100 times. respectively, as fast as the processing of IBAD-YSZ. IBAD-MgO is very attractive in that the processing is very fast. IBAD-MgO also needs additional buffer layer(s). Many materials are being investigated to be used as a buffer layer on top of the MgO. BaZrO$_3$ (BZO) is a good candidate as the buffer layer on top of the IBAD-MgO because it is chemically stable and does not react with YBCO at high temperatures. It also has good lattice match with MgO. The BZO film has been deposited on single crystal MgO, and YBCO film was deposited on BZO/MgO to investigate the possibility of using BZO as both the buffer and capping layer of the CC.C.