Facile Synthesis of p‐type Perovskite SrTi0.65Fe0.35O3–δ Nanofibers Prepared by Electrospinning and Their Oxygen‐Sensing Properties

Quaternary p‐type SrTi 0.65 Fe 0.35 O 3– δ (STFO) nanofibers with diameters ranging from 70 to 500 nm were synthesized via electrospinning and subsequent calcination at 750 °C. The STFO fibers showed single perovskite structure and polycrystalline fiber morphologies composed of small nanocrystallites in the range of 10–12 nm. The semiconducting oxygen sensor using STFO fiber network exhibited a wide temperature‐independence of resistance (≈12 ± 4 kΩ) that exceeded the range of 600–950 °C, high oxygen response ( R_ O_ 2 / R_ O_ 2 R_ N_ 2 . - R_ N_ 2 = 4.08 at 20% O 2 ), and a fast response time ( t = 2.1 s at 20% O 2 ) upon cyclic oxygen exposure. These superior properties were attributed to the high surface‐to‐volume ratio of STFO fiber network and the effective diffusion of oxygen gas onto highly porous STFO‐sensing layers. magnified image