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Nahm, Choon-Woo; Park, Choon-Hyun; Yoon, Hwajoung

doi:10.1023/a:1006781823837

Cited by 49 publications

(11 citation statements)

References 7 publications

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“…Commercial systems, e.g., ZnO-Bi 2 O 3 and ZnO-Pr 6 O 11 cannot be co-fired with a Ag inner-electrode (m.p. 961 • C) in multilayered chip components because of their relatively high sintering temperature above 1000 • C. [4][5][6][7][8] Recent studies have shown that V 2 O 5 , the light-metal oxide, is a promising varistor former, which encouraged many research works, [9][10][11][12][13][14][15][16][17][18] where different ceramic binary systems, ZnO-V 2 O 5 ,w e r e investigated. [9][10][11][12][13][14][16][17][18] Also, effects of adding some different metal oxides and rare earths into the above binary system, on the electrical, dielectric and optical properties have been investigated by several authors, e.g., MnO 2 and Mn 3 O 4 , 19 Mn 3 O 4 and Nb 2 O 5 , 20 24 MnO 2 .…”

Section: Introductionmentioning

confidence: 99%

Mechanical, microstructure and electrical properties of ternary ZnO–V2O5–Mn3O4 varistor with sintering temperature

et al. 2015

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The mechanical, microstructure and electrical properties of the ZnO-V 2 O 5-Mn 3 O 4 (ZVM)-based varistors were investigated at different sintering temperatures of 825-950 • C. The microstructure of the samples consists mainly of ZnO grains with Zn 3 (VO 4) 2 ,Z n V 2 O 4 and VO 2 as minor secondary phases. These minor phases disappeared for samples sintered at 950 • C. Energy-dispersive X-ray spectroscopic (EDS) analysis confirmed the above microstructure results. The sintered density is decreased linearly from 5.45 to 5.30 g cm −3 with an increase in the sintering temperature. The E B-andα-values of ZnO-based varistor can be controlled in a straightforward manner through the control of grain size. The breakdown field exhibited the highest value (2110 V cm −1) at 825 • Ci nt h e sintering temperature and the lowest value (1427 V cm −1)a t9 5 0 • C in the sintering temperature. The non-linear coefficient exhibited the highest value, reaching 19.81 at 875 • C and the lowest value, reaching 6.71 at 850 • C. As the average grain size increases both the longitudinal wave velocity and the longitudinal elastic modulus decrease while the ultrasonic attenuation increases and vice versa. Keywords. Ceramics; electrical properties; microstructure; varistors; ZnO-V 2 O 5-doped Mn 3 O 4 varistor; sintering.

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Section: Introductionmentioning

confidence: 99%

Mechanical, microstructure and electrical properties of ternary ZnO–V2O5–Mn3O4 varistor with sintering temperature

et al. 2015

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“…During this reaction, the trivalent Y 3+ ion replaced a divalent Zn 2+ ion on the lattice through the liberation of a net electron to the conduction band and the formation of positively charged 2Y`Z n . This reaction mechanism assumed that the Y 2 O 3 doping effect on the non-Ohmic properties was related to electronic state at the grain boundary [5], [6]. Figure 5 shows the dielectric constant and the dielectric loss with respect to the frequency of the Y 2 is decreased with increasing amounts of Y 2 O 3 , which was mainly attributed to the high resistivity of the segregation layers 1.42 [M-ohm].…”

Section: Resultsmentioning

confidence: 99%

Voltage Enhancement of ZnO Oxide Varistors for Various Y₂O₃Doping Compositions

Yoon¹,

Lee²,

Lee³

et al. 2009

Transactions on Electrical and Electronic Materials

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The microstructure and the electrical properties of a ZnO varistor, which was composed of a ZnO-Bi 2 O 3 -Sb 2 O 3 -CoO-MnO 2 -NiO-Nd 2 O 3 system, were investigated at various Y 2 O 3 addition concentrations. Y 2 O 3 played a role in the inhibition of the grain growth. As the Y 2 O 3 content increased, the average grain size decreased from 6.8 ㎛ to 4 ㎛, and the varistor voltage(V 1mA ) greatly increased from 275 to 400 V/mm. The nonlinearity coefficient (α) decreased from 72 to 65 with increasing Y 2 O 3 amount. On the other hand, the leakage current (I L ) increased from 0.2 to 0.9 ㎂. These results confirmed that doping the varistors with Y 2 O 3 is a promising production route for production of a higher fine-grained varistor voltage (V 1mA ) which can dramatically reduce the size of the varistors.

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“…Not only the existence of two liquid phases adds to the amount of liquid phases, but also their difference at melting point remarkably widens the temperature range of films' liquid phase annealing. The compatible of the two liquid phases effectively avoids distributing uniformity of the component [13][14][15]. Figure 5 shows Xray diffraction pattern of ZnO films doped with 0.25, 0.5, 0.75, 1.0 mol.% B 2 O 3 , respectively.…”

Section: Study Of Microstructure Compactnessmentioning

confidence: 99%

Study on the ZnO-based ceramic films for low-voltage varistors with high stability

et al. 2007

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ZnO-based ceramic films for low-voltage varistors were fabricated by a novel sol-gel process. The stability of ZnO-based ceramic films has been studied by improving the degradation properties and increasing the microstructure compactness of the films. The degradation of the film varistors was improved via doping with Na + and heat-treating in oxygen ambient. The microstructure compactness was increased via eliminating the microspores and improving uniformity of the grain size of ZnO by doping with B 2 O 3 . The results indicated that ZnO-based ceramic films for lowvoltage varistors with high stability can be obtained while the concentration of doped Na + is 20-40 ppm, B 2 O 3 is 0.25-0.5 mol.% and being heat-treated in oxygen ambient for 2 h.

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Untitled

Cited by 49 publications

References 7 publications

Mechanical, microstructure and electrical properties of ternary ZnO–V2O5–Mn3O4 varistor with sintering temperature

Mechanical, microstructure and electrical properties of ternary ZnO–V2O5–Mn3O4 varistor with sintering temperature

Voltage Enhancement of ZnO Oxide Varistors for Various Y₂O₃Doping Compositions

Study on the ZnO-based ceramic films for low-voltage varistors with high stability

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Untitled

Cited by 49 publications

References 7 publications

Mechanical, microstructure and electrical properties of ternary ZnO–V2O5–Mn3O4 varistor with sintering temperature

Mechanical, microstructure and electrical properties of ternary ZnO–V2O5–Mn3O4 varistor with sintering temperature

Voltage Enhancement of ZnO Oxide Varistors for Various Y2O3Doping Compositions

Study on the ZnO-based ceramic films for low-voltage varistors with high stability

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Voltage Enhancement of ZnO Oxide Varistors for Various Y₂O₃Doping Compositions