ABSTRACT

The effect of the Nd₂O₃ and TiO₂ ratios on the microstructure, dielectric properties and quality factor (Q.f_r) of the 1 wt% Mn-doped BaO-Nd₂O₃-4TiO₂ system were investigated. The samples sintered at various temperatures were analysed by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and a network analyser at 3 GHz. The grains of the Nd₂O₃ poor composition MBN0.5T4 were more spherical, whereas the grains of the excess Nd₂O₃ composition MBN1.5T4 were spherical and rod-like. The grains of the TiO₂ poor composition MBNT4 and the TiO₂rich composition MBNT5 were more rod-like than spherical. The grain size increased with increasing sintering temperature. The BaNd₂Ti5O₁₄ phase was observed for compositions based on a BaO/Nd₂O₃ = 1 ratio. The composition that deviated from the BaO/Nd₂O₃ = 1 ratio was composed of a major phase, BaNd₂Ti5O₁₄, with some secondary phases, Nd₂Ti2O₇ and BaTi₄O₉. The formation of the secondary phases affects the density, dielectric properties and quality factor of the Mn-doped BBaO-Nd₂O₃-4TiO₂ system. The dielectric constant varies from 35–85 with different Nd₂O₃ and TiO₂ contents. Quality factor values of 4200 to 10500 (at 3 GHz) can be obtained by varying the Nd₂O₃ and TiO₂ contents.

DOWNLOAD

Download PDF