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In this paper, the (Ba,Ca)(Ti,Zr)-MLCCs with nickel electrodes by free sintering and constrained sintering as different heating rate have been investigated as different heating rate with 200°C/hr, 1500°C/hr and 3000°C/hr, respectively. The BaTiO3 was adopted as constraining layer due to the tensile stress of generation resulted from the different onset temperature. The electrical characteristics were closely related to the microstructure change including electrode overlap areas and grain size by free and constrained sintering with different heating rate. The variation of dielectric constant and insulation resistance can be explained by grain size change. The variation of dielectric loss can be explained by the curve of the temperature coefficient of capacitance. To compare with the free sintering, the capacitance value of constrained sintering of MLCCs has increased regardless of the heating rates. The high capacitance, high electrode continuity (>98%) and high insulation resistance (>1010Ω) of BCTZ-based MLCC with nickel electrode can be attained by using a rapid constrained sintering technique. [ABSTRACT FROM PUBLISHER]

Abstract: The effect of MnCO3 doped from 0 to 55mol% into BaO–(Nd0.7Sm0.3)2O3–4TiO2 (BNST) sintered in a reducing atmosphere on the microstructure and electrical properties was studied. Mn3+ completely substituted into Ti4+-sites of BNST to form a solid solution, so there is no second phase until 42mol% which is the maximum solubility. Mn (<42mol%)-doped BNST sintered in a reducing atmosphere is in a semi-conducing state because the concentration of free electron is higher than that of the acceptors. On the other hand, when Mn content doped into BNST exceeds a critical value (>43mol%), the second Mn-rich phase due to excess of Mn3+ substituted into Ti4+-site, corresponding to original BaO–(Nd0.7Sm0.3)2O3–4TiO2 (114) phase, is formed. Mn (>43mol%)-doped BNST sintered in a reducing atmosphere is in an insulating state because the concentration of the acceptors is higher than that of liberated free electron, so the insulation resistance becomes high and tan δ becomes low. The formation of the second Mn-rich phase affects Q × f factor and temperature coefficient of capacitance (T.C.C.) of BNST significantly. [Copyright &y& Elsevier]

Abstract: Zinc titanate (ZnTiO3) films were prepared using RF magnetron sputtering at substrate temperatures ranging from 30 to 400°C. Subsequent annealing of the as-deposited films was performed at temperatures ranging from 600 to 900°C. It was found that all as-deposited films were amorphous, as confirmed by XRD. This was further confirmed by the onset of crystallization that took place at annealing temperatures 600°C. The phase transformation for the as-deposited films and annealed films were investigated in this study. The results revealed that pure ZnTiO3 (hexagonal phase) can exist, and was obtained at temperatures between 700 and 800°C. However, it was found that decomposition from hexagonal ZnTiO3 to cubic Zn2TiO4 and rutile TiO2 took place with a further increase in temperature to 900°C. [Copyright &y& Elsevier]