Effect of rare earth oxides on the microstructure and microwave dielectric properties of CaO−MgO−Nb2O5−TiO2 system ceramics

Wang Hao; Chen Wen; Liu Tao

doi:10.1007/BF02841290

Journal of Wuhan University of Technology Materials Science Edition ›› 2005, Vol. 20 ›› Issue (4) : 83 -86. DOI: 10.1007/BF02841290

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Effect of rare earth oxides on the microstructure and microwave dielectric properties of CaO−MgO−Nb₂O₅−TiO₂ system ceramics

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Abstract

La₂O₃ and SrO-doped CaO−MgO−Nb₂O₅−TiO₂ system ceramics were prepared by solid-state ceramic technique. The microstructure and microwave dielectric properties of CaO−MgO−Nb₂O₅−TiO₂−La₂O₃ ceramics can be adjusted by varying the amount of La³⁺ or Sr²⁺ ions respectively. The replacement of Ca²⁺ by La³⁺ at A-site of the ceramics increases the quality factor Q value (at 7.6 GHz) as well as the temperature coefficient of resonant frequency τ_f and decreases the dielectric constant ɛ, and the substitution of Sr²⁺ at A-site in this ceramics system exhibits opposite characteristics. The microwave properties of La³⁺, Sr²⁺-doped CaO−MgO−Nb₂O₅−TiO₂ system ceramics depend on the degree of octahedral distortion inside materials.

Keywords

perovskite / microwave dielectric ceramic / dielectric properties

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Wang Hao, Chen Wen, Liu Tao. Effect of rare earth oxides on the microstructure and microwave dielectric properties of CaO−MgO−Nb₂O₅−TiO₂ system ceramics. Journal of Wuhan University of Technology Materials Science Edition, 2005, 20(4): 83-86 DOI:10.1007/BF02841290

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