The effect of NH4+ on shape modulation of La1−xSrxMnO3 crystals in a hydrothermal environment
Perovskite oxide (La1−xSrxMnO3) crystal facet control is rarely reported due to difficulties in modulation, even though it is highly important in surface-dependent catalytic and electrochemical applications. In this paper, we present the shape diversity of La1−xSrxMnO3 crystals evolved from a hydrothermal environment when urea is used as an effective facet modulator. By changing the La/Sr ratio from 1 to 3, the structure changes from pseudo-cubic to P21/a monoclinic, induced by the evolution processes of different facets during crystallization. Our proposed hypothesis is that the NH4+ interaction with octahedral MnO6 may be beneficial in enhancing the activity of La1−xSrxMnO3 for applications, and moves toward strategies for the development of highly active perovskite oxides.