⁵⁷Fe CEMS study on dilute metal ions codoped SnO₂ thin films prepared by spray pyrolysis

Abstract

Dilute Mn-Fe, Co-Fe and V-Fe codoped tin oxide films prepared by spray pyrolysis were characterized by ⁵⁷Fe conversion electron Mössbauer spectrometry (CEMS) at room temperature (RT) and at 20 K. Two kinds of paramagnetic Fe³⁺ species were detected at RT; one doublet 1 (D1) with IS = 0.36–0.37 mm/s, QS = 0.69–0.75 mm/s and LW = 0.32–0.40 mm/s, and another doublet 2 (D2) with IS = 0.31–0.35 mm/s QS = 1.16–1.25 mm/s and LW = 0.46–0.52 mm/s. CEMS at 20 K provided more distinguished doublets than at RT. It is found that especially D2 with relatively small IS and large QS values are influenced by other metal ions codoped in SnO₂ matrix, whereas D1 with relatively large IS and small QS has the parameters close to the models of Fe-VO1 and Fe-2VO1-Fe models (Nomura et al. Phys. Rev. B 75, 184411 2007; Mudarra Navarro et al. J. Phys. Chem. C 119, 5596–5603 2015).