Local A‐Site Layering in Rare‐Earth Orthochromite Perovskites by Solution Synthesis

Cation size effects were examined in the mixed A‐site perovskites La₀.₅Sm₀.₅CrO₃ and La₀.₅Tb₀.₅CrO₃ prepared through both hydrothermal and solid‐state methods. Atomically resolved electron energy loss spectroscopy (EELS) in the transmission electron microscope shows that while the La and Sm cations are randomly distributed, increased cation‐radius variance in La₀.₅Tb₀.₅CrO₃ results in regions of localised La and Tb layers, an atomic arrangement exclusive to the hydrothermally prepared material. Solid‐state preparation gives lower homogeneity resulting in separate nanoscale regions rich in La³⁺ and Tb³⁺. The A‐site layering in hydrothermal La₀.₅Tb₀.₅CrO₃ is randomised upon annealing at high temperature, resulting in magnetic behaviour that is dependent on synthesis route.