**Appendix A**


**Table A1.** Binding energies of LaMnO3.15 and LaFeO3 samples' XPS components.

<sup>1</sup> values corresponding to OI/OII/OIII type species.

**Figure A1.** High-resolution spectra of La 3d and Mn 2p core level spectra for LaMnO3.15 samples: (a) SSR, solid state reaction; (b) HEBM, high-energy ball milling; (c) LEBM, low-energy ball milling.

**Figure A2.** High-resolution spectra of La 3d core level spectra for LaFeO3 samples: (a) SSR, solid state reaction; (b) HEBM, high-energy ball milling; (c) LEBM, low-energy ball milling.
