The perovskite compound SrMoO₃ has been recently considered as an alternative plasmonic material. SrMoO₃ remains optically metallic after being annealed in air up to 500°C, and up to 700°C if a pre-annealing in nitrogen is performed. This figure shows an SMO sample after annealing at 700°C. See Wells et al. Optical Materials Express 8, 1806-1817 (2018).