Figure 5.

Quantitative reversibility of the EPR signal of Mn:SrTiO₃ bulk powder as-prepared (solid black line), after T_red at 400°C (solid orange line), and after T_air at 500°C for ~1 h (gray dotted line). The weak Mn⁴⁺ and Mn²⁺ features after NaBH₄ reduction are still observed in the 50× scaled spectra (orange dotted lines).