Mn-substituted spinel Li4Ti5O12 materials studied by multifrequency EPR spectroscopy

Hülya Kaftelen, Mustafa Tuncer, Suyan Tu, Sergei Repp, Hasan Göçmez, Ralf Thomann, Stefan A. L. Weber, Emre Erdem

Journal of Materials Chemistry A · 2013 · 77 citations · 59 references

Concepts

Abstract

In this contribution we report on the influence of Mn doping on various physical properties of Li4Ti5−xMnxO12 (x = 0, 0.005, 0.025, 0.01, 0.05, 0.075, 0.1 and 0.2). Spinel-type (space group Fd3m, a = 0.8358 nm) Li4Ti5−xMnxO12 was produced as highly uniform and polyhedral shaped powder in a size range between 200 and 400 nm. The crystal structure of Li4Ti5−xMnxO12, the morphology and the Mn-ion distribution have been investigated by X-ray diffraction (XRD) and scanning and transmission electron microscopies (SEM and TEM). The oxidation state of Mn and the conductivity behavior of Mn-substituted Li4Ti5−xMnxO12 samples have been studied using multi-frequency electron paramagnetic resonance (EPR). Mn is incorporated as Mn2+, and these ions increase the conductivity of Li4Ti5O12; a conductivity value of 0.48 × 10−8 S cm−1 was measured for Li4Ti5−xMnxO12 with x = 0.075, which is ten-fold larger than that of undoped Li4Ti5O12.

References

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