• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.05c
• /
• pp.123-126
• /
• 2001

The $0.98MgTiO_3-0.02BaTiO_3$ ceramics were prepared by the conventional mixed oxide method. The structural properties were investigated with sintering temperature and composition ratio by XRD, SEM and EDS. According to the X-ray diffraction patterns of the $0.98MgTiO_3-0.02BaTiO_3$ ceramics, the hexagonal $BaMg_6Ti_6O_{19}$ and ilmenite $MgTiO_3$ structures were coexisted. The dielectric constant$({\varepsilin}_r)$ and quality factor$(Q{\times}f_r)$ were decreased with increasing the sintering temperature in the range of $1275^{\circ}C{\sim}1350^{\circ}C$. In the case of the $0.98MgTiO_3-0.02BaTiO_3$ ceramics sintered at $1275^{\circ}C$, dielectric constant, quality factor and temperature coefficient of resonant frequency were 20.27, 76,845, $-46.6ppm/^{\circ}C$, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.4
• /
• pp.317-321
• /
• 2003

In this study, the structural properties were Investigated for the deposited (Ba,Sr)(Nb,Ti)O$_3$[BSNT] thin films grown on Pt/TiO$_2$/SiO$_2$/Si substrate by RF sputtering method. The structural properties of the BSNT thin films affected by the Ar/02 ratios were Investigated. In the case of the BSNT thin films deposited with condition of 60/40(Ar/O$_2$) ratio, the BaTiO$_3$, SrTiO$_3$ and BaNbO$_3$ phases were showed. The composition ratio of Nb and Ti in the BSNT thin films were nearly equivalent. Also, in the BSNT thin films deposited with condition of 60/40 and 80/20(Ar/O$_2$) ratios, the composition of Ba, Sr, Nb and Ti were relatively uniform. The Ba, Sr, Nb and Ti in the BSTN thin films were not diffused into the Pt layer.

• Korean Journal of Materials Research
• /
• v.33 no.12
• /
• pp.517-524
• /
• 2023

BaTiO₃-Poly vinylidene fluoride (PVDF) solution was prepared by adding 0~25 wt% BaTiO₃ nanopowder and 10 wt% PVDF powder in solvent. BaTiO₃-PVDF film was fabricated by spreading the solution on a glass with a doctor blade. The output performance increased with increasing BaTiO₃ concentration. When the BaTiO₃ concentration was 20 wt%, the output voltage and current were 4.98 V and 1.03 ㎂ at an applied force of 100 N. However, they decreased when the over 20 wt% BaTiO₃ powder was added, due to the aggregation of particles. To enhance the output performance, the generator was poled with an electric field of 150~250 kV/cm at 100 ℃ for 12 h. The output performance increased with increasing electric field. The output voltage and current were 7.87 V and 2.5 ㎂ when poled with a 200 kV/cm electric field. This result seems likely to be caused by the c-axis alignment of the BaTiO₃ after poling treatment. XRD patterns of the poled BaTiO₃-PVDF films showed that the intensity of the (002) peak increased under high electric field. However, when the generator was poled with 250 kV/cm, the output performance of the generator degraded due to breakdown of the BaTiO₃-PVDF film. When the generator was matched with 800 Ω resistance, the power density of the generator reached 1.74 mW/m². The generator was able to charge a 10 ㎌ capacitor up to 1.11 V and turn on 10 red LEDs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1998.06a
• /
• pp.335-338
• /
• 1998

The effect of glass flit addition on microwave dielectric properties of BaTiO$_3$-3TiO$_2$ ceramic was studied. Addition of glass frit to this system obtained sintered sample below sintering temperature 105$0^{\circ}C$. At BaTiO$_3$-3TiO$_2$+ g1ass frit 3wt% + BaWO$_4$6 wt%m, this ceramic showed excellent microwave properties of dielectric constant 34, Q$\times$f 8,100, temperature coefficient of resonant frequency 4 ppm/$^{\circ}C$ .

• Journal of the Korean Ceramic Society
• /
• v.33 no.7
• /
• pp.743-754
• /
• 1996

In this study (Ba1-xPbx)TiO3 was synthesized by modified oxalate process in order to prevent vaporization of PbO through low temperature synthesis climinate Cl ion reproducibly substitute Pb for by and uniformly distribute ion (Ba1-xPbx)TiO3 was synthesized by coprecipitation of lead acetate barium acetate and ammonium titanyl oxalate have been used as starting materials. The substitution of Pb for Ba was reproducibly possible synthetic temperature of perovskite structure becomes lowed as the Pb concentration increases and fine partic-les (specific surface are :7.2 cm2/g) were obtained, BaTiO3 powders calcined at 90$0^{\circ}C$ for 3 hours were cubic from in XRD analysis and as Pb content was increases evident split of tetragonal peaks could be observed The optimum conditions to synthesize (Ba,Pb)TiO3 powder are the followings ; synthesis temperature (5$^{\circ}C$)

• Journal of the Korean Ceramic Society
• /
• v.21 no.3
• /
• pp.278-282
• /
• 1984

Barium titanate powder was made by firing the complex hydroxide which had been synthesized with chemical wet process by the medium of $H_2O_2$. This experiment was done as following A mixed solution of $BaCl_2$, $TiCl_4$ and $H_2O_2$ with 1:1:10 mol ratio was prepared. Ammonium hydroxide was added into the mixed solution. In the range of pH 8-10 $BaTiO_3$ complex hydroxide was obtained and treated at room temperature 11$0^{\circ}C$, 20$0^{\circ}C$, 40$0^{\circ}C$ and $600^{\circ}C$. The results obtaiined from this experiment were as follows. At room temperature $BaTiO_3$ complex hydroxide was amorphous. Above 10$0^{\circ}C$ crystalline $BaTiO_3$ was obtained and particle size of $BaTiO_3$ was increased with elevated temperature. So the particle size of BaTiO3 could be controlled by the firing temperature. After treating $BaTiO_3$ complex hydroxide at 10$0^{\circ}C$ the average particle size of $BaTiO_3$ was 0.22$\mu\textrm{m}$.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.55 no.6
• /
• pp.291-296
• /
• 2006

In this study, the sputtered BTO film was polished by CMP process with the self-developed $BaTiO_3$- and $TiO_2$-mixed abrasives slurries (MAS), respectively. The removal rate of BTO ($BaTiO_3$) thin film using the $BaTiO_3$-mixed abrasive slurry (BTO-MAS) was higher than that using the $TiO_2$-mixed abrasives slurry ($TiO_2$-MAS) in the same concentrations. The maximum removal rate of BTO thin film was 848 nm/min with an addition of $BaTiO_3$ abrasive at the concentration of 3 wt%. The sufficient within-wafer non-uniformity (WIWNU%) below 5% was obtained in each abrsive at all concentrations. The surface morphology of polished BTO thin film was investigated by atomic force microscopy (AFM).

• Electrical & Electronic Materials
• /
• v.10 no.7
• /
• pp.674-681
• /
• 1997

Ternary compound ceramics, (1-y-x) BaTiO$_3$-y SrTiO$_3$-x MgTiO$_3$(0.00 x 0.20), were fabricated by the conventional ceramic process. The structural and dielectric properties of specimens were investigated while varying the composition and sintering temperature(1,200~1,45$0^{\circ}C$) in order to obtain the optimum condition of capacitor. As is well known, Curie temperature(T$_{c}$) of high dielectric-based ceramic(BaTiO$_3$) was shifted and temperature of capacitance was decreased in according to increase of solid solution with (Sr, Mg)TiO$_3$. As a result, a suitable condition of compound rate for capacitor was obtained such as the BSM-11(0.8BaTiO$_3$-0.1SrTiO$_3$-0.1MgTiO$_3$), and sintering temperature was sintered at 1,25$0^{\circ}C$ for two hours. In this case, dielectric constant<1,300, dielectric loss(tan$\delta$)<0.03, and the variation rate of capacitance had less than 3% in the range -10~7$0^{\circ}C$.>.

• Journal of Magnetics
• /
• v.11 no.4
• /
• pp.164-166
• /
• 2006

We have investigated the dielectric and magnetic properties of ferroelectric-antiferromagnetic $BaTiO_{3}-LaMnO_{3}$ composite with changing relative mole percents. Due to high sintering temperature, i.e. $1150^{\circ}C$, the Ba ion in $BaTiO_{3}$ seems to diffuse into $LaMnO_{3}$; resulting in $BaTiO_{3}-(La,Ba)MnO_{3}$ ferroelectric-ferromagnetic composite. At room temperature, $0.9BaTiO_{3}-0.1LaMnO_{3}$ composite exhibits considerable magnetization (${\sim}0.7\;emu/g\;at\;2000\;Oe$) and low coercive field (${\sim}5\;Oe$). Also it exhibits high dielectric constant (${\sim}560$) and low loss (${\sim}0.08$) at 10 kHz. This result may imply that $BaTiO_{3}-LaMnO_{3}$ could be suitable for a low leakage multiferroic composite.

• Journal of the Microelectronics and Packaging Society
• /
• v.9 no.2
• /
• pp.11-17
• /
• 2002

Polymer/ceramic composite is of great interest as a dielectric material for embedded capacitors. This paper is concerned in the effects of $BaTiO_3$ particle size on epoxy/$BaTiO_3$ composite films for embedded capacitors. 6 different size powders smaller than 1 $\mu\textrm{m}$ in diameter and bisphenol-A type epoxy were used for this experiment. Dielectric constant of the epoxy/$BaTiO_3$ composite capacitors increases as the powder size increases at the same powder loading, which is due to the increase of tetragonality of the powders as particle size increases. And leakage current of the capacitors also increases dramatically as the powder size increases. It was explained that this is due to the decrease of the number of $BaTiO_3$epoxy/$BaTiO_3$ potential barriers per unit length and, moreover, the enhancement of potential barrier lowering effects caused by increase of potential drop per one barrier. As a result, there is tradeoff between high dielectric constant and low leakage current in the epoxy/$BaTiO_3$ composite capacitors. So it is important to select proper size $BaTiO_3$ powders in accordance with needs.