Hasla Co.

Kang-neung, South Korea

Hasla Co.

Kang-neung, South Korea
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Yoon S.-O.,Gangneung - Wonju National University | Kim Y.-H.,Gangneung - Wonju National University | Kim S.,Hasla Co. | Jeong S.-M.,Korea Institute of Ceramic Engineering And Technology | Park H.,Korea Polytechnic University
Journal of Ceramic Processing Research | Year: 2017

Sintering behavior and microwave dielectric properties of Li2O and In2O3 doped zinc orthosilicate having the composition of Zn1.9Si1.05O4, i.e. the Zn1.9-2xLixInxSi1.05O4 system where x = 0.01~0.06, were investigated. The liquid phase occurred by sintering contributed to the densification. As the amount of Li2O and In2O3 increased, the temperature indicating the maximum value of bulk density in each composition decreased from 1250°C to 1050°C. And the value of dielectric constant against sintering temperature showed a similar tendency. Also, the value of quality factor decreased as the amount of Li2O and In2O3 increased. The dielectric constant and the quality factor of the composition of x = 0.02 sintered at 1150°C were 6.49 and 55,437 GHz, respectively. © 2017, Hanyang University. All rights reserved.


Kim S.,Hasla Co. | Yoon S.-O.,Gangneung - Wonju National University | Kim Y.-H.,Gangneung - Wonju National University | Jeong S.-M.,Korea Institute of Ceramic Engineering And Technology | Park H.,Korea Polytechnic University
Ceramics - Silikaty | Year: 2017

Microstructure, phase evolution, and microwave dielectric properties of Li2O and Ga2O3 doped zinc orthosilicate having the composition of Zn1.9Si1.05O4, i.e. the Zn1.9-2xLixGaxSi1.05O4 system where x = 0.02 ~ 0.10, were investigated. LiGaSiO4 and ZnGa2O4 are observed as the secondary phase. The densification occurred by the liquid phase in the all specimens. The densification curves showed a sigmoidal shape. As the amount of Li2O and Ga2O3 increased, the temperature indicating the maximum value of bulk density in each composition decreased from 1250°C to 1100°C. The value of dielectric constant against the sintering temperature showed a similar tendency as that of the bulk density. The presence of the liquid phase and the insufficient grain growth may cause the deterioration of the quality factor. The dielectric constant and the quality factor of the specimen of x = 0.08 sintered at 1100°C were 6.28 and 27.097 GHz, respectively.


Kim Y.-H.,Gangneung - Wonju National University | Kim S.,Hasla Co. | Jeong S.-M.,Korea Institute of Ceramic Engineering And Technology | Kim S.-J.,Hanzhong University | Yoon S.-O.,Gangneung - Wonju National University
Journal of the Korean Ceramic Society | Year: 2015

Phase evolution, microstructure, and microwave dielectric properties of Li2O and Al2O3 doped Zn1.9Si1.05O4, i.e., Zn1.9-2xLixAlxSi1.05O4, ceramics (x = 0.02 ∼ 0.10) were investigated. The ceramics were densified by SiO2-rich liquid phase composed of the Li-Al- Si-O system, indicating that doped Li and Al contributed to the formation of the liquid. As the secondary phase, β-spodumene solid solution with the composition of LiAlSi3O8 was precipitated from the liquid during the cooling process. The dense ceramics were obtained for the specimens of ≥ 0.06 showing the rapid densification above 1000°C, implying that a certain amount of liquid is necessary to densify. The specimen of x = 0.06 sintered at 1050°C exhibited good microwave dielectric properties; the dielectric constant and the quality factor (Q × f0) were 6.4 and 11,213 GHz, respectively.


Byeon D.-S.,Korea Institute of Ceramic Engineering And Technology | Byeon D.-S.,Yonsei University | Jeong S.-M.,Korea Institute of Ceramic Engineering And Technology | Hwang K.-J.,Korea Institute of Ceramic Engineering And Technology | And 5 more authors.
Journal of Power Sources | Year: 2013

A computational study employing classical molecular dynamics techniques was employed to explore the diffusion of oxide ions in Ba-doped LaInO3, a cubic perovskite oxide. The Ba dopant in the LaInO3 forms oxygen vacancies that function as charge carriers via an oxygen diffusion mechanism. Previous experimental studies reported that the ionic conductivity of Ba-doped LaInO3 decreases with increasing numbers of oxygen vacancies, which was not fully understood through experimental approaches. Hence, this study explored the diffusion pathway for individual oxygen vacancies through molecular dynamics simulation. Based on the findings of this study, the Ba dopant appears to form narrow bottlenecks that function as a barrier to the movement of oxide ions. We concluded that the oxide ion conductivity of Badoped LaInO3 is affected by the local ionic distribution of the Ba dopant. © 2012 Elsevier B.V. All rights reserved.


Kim H.-L.,Yonsei University | Kim S.,Hasla Co. | Lee K.-H.,Kangwon National University | Lee H.-L.,Yonsei University | Lee K.-T.,Chonbuk National University
Journal of Power Sources | Year: 2014

Oxygen ion conduction behaviors of the 0-5 mol% excess Ba-doped La 0.6Ba0.4InO3-δ cubic perovskite oxides have been investigated to elucidate their potential as electrolyte materials. The highest conductivity, 5.6 × 10-2 S cm-1 at 800 °C, is obtained at the 3 mol% excess Ba-doped composition benefiting from a supplementation of Ba2+ ions on the vacant A-site generated by the volatilization during the heat-treatment processes. Interestingly, all the samples except the undoped composition show curved electrical conductivity behavior in the Arrhenius plot. The activation energy is 0.50-0.52 eV in the high-temperature region above 900 °C, which is slightly lower than that of the doped LaGaO3 system. Moreover, all the samples show significantly lower activation energy values of both the high- and low-temperature regions compared with yttria-stabilized zirconia. The 3 mol% excess Ba-doped La 1-xBaxInO3-δ (0.4 ≤ x ≤ 0.8) sample has also been studied. All of the compositions show a cubic perovskite structure and a nearly pure oxygen ion conduction behavior in a dry atmosphere even when p(O2) = 1atm. The composition of x = 0.4 exhibits the highest oxygen ion conductivities. © 2014 Elsevier B.V. All rights reserved.

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