Stoichiometry and Grain Boundaries Control by Spark Plasma Sintering in Ba0.6 Sr0.4 TiO3: Mn/ MgO Composites.

This study highlights the possibility to control materials' chemistry simultaneously at the atomic and micrometric scales and to design functional oxide-based multimaterials, thanks to the specificity of Spark Plasma Sintering ( SPS). We have used a dual synthesis route, namely chemical and composite, combined with SPS to adjust the oxidation state of intrinsic and dopant ions, the grain boundaries state, and to control interdiffusion in composites made of Mn-doped Ba_0.6 Sr_0.4 TiO₃ ( BST) and MgO. At the atomic level, the Mn substituent valence state can be fixed according to the sintering process: Electron Paramagnetic Resonance evidenced [ABSTRACT FROM AUTHOR]