Synthesis and characterization of monoclinic rare earth titanates, RE2Ti2O7 (RE = La, Pr, Nd), by a modified SHS method using inorganic activator

[摘要] The nano particles of phase pure rare earth titanates, synthesized by the SHS technique, get well sintered at lower temperatures compared to the compounds formed by the solid-state method. These dielectrics are highly stable and can be used in the microwave frequency range. We report here a modified SHS method to synthesize phase pure monoclinic RE₂Ti₂O₇ at 350°C through the oxide/nitrate precursors using an inorganic compound, ammonium acetate, in place of the general type of organic activators such as urea, alanine etc. The nanopowders of La₂Ti₂O₇, Pr₂Ti₂O₇ and Nd₂Ti₂O₇ on heating exhibit an exothermic behaviour with a broad maxima in the range 267â€�??284°C and become endothermic with maxima in the range 1043â€�??1220°C; interestingly, the phase pure crystalline material is formed at the temperature of exothermic maxima, as confirmed by XRD.

[学科分类] 材料工程

[关键词] Rare earth titanates;SHS;phase pure RE2Ti2O7;inorganic activator;MW dielectrics;nano particles.