| $Sr(Zr, Ti)O_3$ 마이크로파 유전체에 첨가된 $Mn_2O_3, Y_2O_3$ 의 영향과 Mn의 산화상태 |
| 정하균, 박도순, 박윤창1 |
한국화학연구소 기초연구실
1성균관대학교 화학과 |
| Effects of $Mn_2O_3, Y_2O_3$ Additives and Valence State of Mn ion in $Sr(Zr, Ti)O_3$ Microwave Dielectrics |
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| ABSTRACT |
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The effects of Mn2O3 and Y2O3 additives on the microstructure and dielectric properties of Sr(Zr, Ti)O3 have been investigated. Powders with Sr(Zr1-xTix)O3(0$leq$x$leq$0.1) composition were prepared by the conventional solid state processing from commercial TiO2 and precipitation-processed ZrO2. The powders containing sintering additives of Mn2O3 and Y2O3 were compacted and then sintered at 1,55$0^{circ}C$ for 4 h to get>97% relative density. Mn2O3 suppressed the grain growth and Y2O3 enhanced the density of sintered body. The oxidation state of Mn ions were determined by a chemical wet method and EPR spectroscopy. Mn ions were present as Mn2+ and Mn4+ in SrZrO3, while as Mn3+ and Mn4+ in Ti-substituted Sr(Zr, Ti)O3. With the substitution of Ti, the lattice parameters of SrZrO3 decreased and its dielectric constant increased with remarkable decrease in Q value. The dielectric constant of Sr(Zr, Ti)O3 was in the range of 30 to 40, Q values 1,200~5,400 at 6 GHz and temperature coefficient of resonant frequency -67~100 ppm/K. |
| Key words:
Microwave dielectrics, Strontium zirconate, EPR, Mn valency, Rietveld method. |
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