Direct Syntheses of Mixed Ion and Electronic Conductors La₄Ni₃O₁₀ and La₃Ni₂O₇ from Nanosized Coprecipitates

Nanoparticle coprecipitates of lanthanum hydroxide and nickel hydroxide were synthesized in a continuous hydrothermal flow synthesis system. Two such coprecipitates with the appropriate La:Ni molar ratios were subsequently directly converted to phase-pure La4Ni3O10 and La3Ni2O7, respectively, via a single heat-treatment step in each case.