• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.146-150
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• 2005

Two new barium vanadium borophosphate compounds, $(NH_4)_2(C_2H_{10}N_2)_6[Ba(H_2O)_5]_2[V_2P_2BO_{12}]_6{\cdot}8H_2O$, Ba- VBPO1 and $(NH_4)_8(C_3H_{12}N_2)_4[Ba(H_2O)_7][V_2P_2BO_{12}]_6{\cdot}17H_2O$, Ba-VBPO2 have been synthesized by interdiffusion methods in the presence of diprotonated ethylenediamine and 1,3-diaminopropane. Compound Ba-VBPO1 has an infinite chain anion (${[BaH_2O)_5]_2[V_2P_2BO_{12}]_6}$$^{14-}$, whereas Ba-VBPO2 has a discrete cluster anion {[$Ba(H_2O)_7][V_2P_2BO_{12}]_6$}$^{16-}$. Crystal Data: $(NH_4)_2(C_2H_{10}N_2)_6[Ba(H_2O)_5]_2[V_2P_2BO_{12}]_6{\cdot}8H_2O$, triclinic, space group P$\overline{1}$ (no. 2), a = 13.7252(7) $\AA$, b = 15.7548(8) $\AA$, c = 15.8609(8) $\AA$, α = 63.278(1)$^{\circ}$, $\beta$ = 75.707(1)$^{\circ}$, $\gamma$ = 65.881(1)$^{\circ}$, Z = 1; $(NH_4)_8(C_3H_{12}N_2)_4[Ba(H_2O)_7][V_2P_2BO_{12}]_6{\cdot}17H_2O$, monoclinic, space group C2/c (no. 15), a = 31.347(2) $\AA$, b = 17.1221(9) $\AA$, c = 22.3058(1) $\AA$, $\beta$ = 99.303(1)$^{\circ}$, Z = 4.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.125-128
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• 1997

The most effective cytokinin source for adventitious shoot regeneration of in vitro grown leaves from 'Gala' apple was BA with the concentration of 4.0 mg/L, while auxin source was IAA, IBA and NAA with the concentration of 0.1 mg/L, respectively. As the result of combinational treatment of BA and NAA, 6.0 or 8.0 mg/L BA with 0.5 mg/L NAA was effective for adventitious shoot regeneration from leaf tissues of 'Gala', 0.1 mg/L NAA + 8.0 mg/L BA and 1.0mg/L NAA + 8.0 mg/L BA for internode, and 0.1 mg/L NAA + 4.0 mg/L BA for petiole.

• Proceedings of the Korean Magnestics Society Conference
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• 1997.11a
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• pp.118-119
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• 1997

• Journal of the Korean Ceramic Society
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• v.26 no.6
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• pp.737-746
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• 1989

After Ba-ferrite powders synthesized hydrothermally and its heated powders were dissolved partially with HCl treatment time, the BaO/Fe2O3 mole ratio of dissolved solutions and powders were measured by AAS, also, lattice constants, particle morphology and magnetic properties in HCl treated, heated and no-heated Ba-ferrite powders were abtained by means of XRD, SEM and VSM, respectively. From above analysis results, the effect of Ba/Fe mole ration in suspension(as starting material) on the BaO/Fe2O3 composition and particle characteristics of products were investigated, and the effect of heat treatment on magnetic properties of products examined. The composition, lattice constant and crystal phase of products depend on the Ba/Fe mole ratio in suspension. Ba content in surface or outer part of Ba-ferrite powder is higher than inner and heterogeneous, and the excess Ba ions in the inner part of particle move into the outer by heating, so that the mole ratio of BaO/Fe2O3 in the more jinner approaches more to the stoichiometric composition 1 : 6. The crystallinity, coercivity and saturation magnetization of products are increased by heat treatment, and the heat-treated samples synthesized hydrothermally in lower temperature are appreciated to have better powder characteristics.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.6
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• pp.495-500
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• 2009

The ceramic($BaTiO_3$)-polymer(epoxy) composites have been widely investigated as dielectric materials for embedded capacitors in printed circuit boards (PCBs). The dielectric properties of $BaTiO_3$/epoxy composites prepared using the agglomerated $BaTiO_3$ particles were investigated in the present study. The dielectric constants of the composites prepared using the agglomerated $BaTiO_3$ particles were about 2 times higher than those of the composites with the dispersed $BaTiO_3$ particles. The insulation resistance of the composites prepared using the agglomerated $BaTiO_3$ particles were lower than those of the composites with dispersed $BaTiO_3$ particles. As a result, there is tradeoff between high dielectric constant and insulation resistance in the $BaTiO_3$/epoxy composites. So it is important to select proper agglomerated or dispersed $BaTiO_3$ particles in accordance with needs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.127-130
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• 2001

The $BaTiO_3+xNb_2O_5$(x=6, 8, 10wt%) ceramics were prepared by conventional mixed oxide method. The structural properties of the $BaTiO_3+Nb_2O_5$ ceramics with the sintering temperature and addition of $Nb_2O_5$ were investigated by XRD and SEM. Increasing the sintering temperature, the $2{\theta}$ value of BT(110) peak was shifted to the lower degree and intensity of the $Ba_6Ti_2Nb_8O_{30}$ (133) peak was increased. Increasing the addition of $Nb_2O_5$, the intensity of $BaTiNb_4O_{13}$ (201) peak was decreased and $Ba_6Ti_2Nb_8O_{30}$ (133) peak was increased. The grain size of the $BaTiO_3+Nb_2O_5$ ceramics sintered at $1500^{\circ}C$ were almost uniform.

• Analytical Science and Technology
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• v.15 no.1
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• pp.15-19
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• 2002

The pretreatment of tungsten added $BaTiO_x$ ceramics was performed to improve the recovery of Ba, Ti and W. $BaTiO_x$ ceramics were digested with HF : HCl ( 1 : 2 ) mixture in an acid digestion bomb at $220^{\circ}C$ for 3 hrs. The concentration of Ba, Ti and W were determined by ICP-AES. Recoveries of Ba, Ti and W were 99.6%, 99.8% and 99.2%, respectively. And their C.V. values were 1.02%, 0.73% and 1.79%. Using this method, the analytical results of Ba, Ti and W for a real sample were obainted to be 25.9% (w/w), 38.8% (w/w) and 3.31% (w/w), respectively.

• 전자공학회논문지 IE
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• v.43 no.2
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• pp.7-10
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• 2006

A GaN-based metal-insulator-semiconductor (MIS) structure has been fabricated by using $BaTa_2O_6$ instead of conventional oxide as insulator gate. The leakage current o) films are in order of $10^{-12}-10^{-13}A/cm^2$ for GaN on $Al_2O_3$(0001) substrate and in order of $10^{-6}-10^{-7}A/cm^2$ for GaN on GaAs(001) substrate. The leakage current of thses films is governed by space-charge-limited current over 45 MV/cm in case of GaN on $Al_2O_3$(0001) substrate and by Poole-Frenkel emission in case of GaN on GaAs(001).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.383-386
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• 2000

The 0.6Ba(Zn$_{1}$3/Ta$_{2}$3/)O$_3$-0.4Ba(Co$_{1}$3/Nb$_{2}$3/)O$_3$ceramics were prepared by the conventional mixed oxide method. The structural properties of the 0.6BZT-0.4BCN ceramics with the sintering temperature were investigated by XRD, SEM. The 0.6BZT-0.4BCN ceramics had a complex-perovskite structure. Increasing the sintering temperature, the peak intensity of the superstructure reflection plane were increased and the density and ordering were increased. The density of the 0.6BZT-0.4BCN ceramics sintered at 1475$^{\circ}C$ was 6.455[g/cm$^3$].

• Journal of the Korean institute of surface engineering
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• v.56 no.6
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• pp.380-385
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• 2023

In this study, an MPB PMNT system containing 0.05 to 0.10 wt.% BaTiO₃ was synthesized using a traditional chemical method and its pyroelectricity was investigated. Pyroelectricity, dielectricity, and ferroelectricity of the synthesized BaTiO₃-PMNT system were analyzed by heat treatment at 1240~1280 ℃ for 4 hours to evaluate its applicability as a pyroelectric sensor. Unlike the simple ABO₃ ferroelectric, the BaTiO₃-doped PMNT system exhibited phase transition characteristics over a wide temperature range typical of complex perovskite structures. Although no dramatic change could be confirmed depending on the amount of BaTiO₃ added, stable pyroelectricity was maintained near room temperature and over a wide temperature range. When the amount of BaTiO₃ added increased from 0.05BaTiO₃-PMNT to 0.10BaTiO₃-PMNT, the electric field slightly increased from 5.00×10³ kV/m to 6.75×10³ kV/m, and the maximum value of remanent polarization slightly increased from 0.223 C/m² to 0.234 C/m². The pyroelectric coefficients of 0.05BaTiO₃-PMNT and 0.10BaTiO₃- PMNT at room temperature were measured to be ~0.0084 C/m²K and ~0.0043 C/m²K, respectively. The relaxor ferroelectric properties of the BaTiO₃-PMNT system were confirmed by analyzing the plot of K_max/K versus (T-T_max)^γ. The BaTiO₃-doped MPB PMNT system showed a distinct pyroelectric performance index at room temperature, and the values were F_v ~ 0.0362 m²/C, F_d ~ 0.575×10^-4 Pa^-1/2.