Microstructural characterization of CoMnFeO₄thin films deposited by radio-frequency sputtering

Abstract

Abstract. CoMnFeO 4 thin films are stable materials useful to study the influence of radio-frequency sputtering experimental conditions, on the microstructure of oxide films. From various techniques of electronic microscopy, gas adsorption techniques and ellipsometry measurements, it was shown that such oxides films prepared with 0.5 Pa sputtering argon pressure and 5 cm target-substrate distance are very dense. On the other hand, the samples obtained under higher pressure and/or longer distance, are microporous. This porosity is mainly due to shadowing and energetic effects of sputtered particles. According to different characterization techniques, a simple model is proposed to describe the microstructure of the films studied.

Elucidation of the Conversion Reaction of CoMnFeO4 Nanoparticles in Lithium Ion Battery Anode via Operando Studies

“…Additionally, cubic MnO exhibits a larger lattice parameter compared to Fe 1– x O and CoO leading to an asymmetric shape of the reflections (simulated powder pattern: Figure S3). On the basis of the present results and those reported in the literature it is most likely that Li uptake gradually forces the formation of a mixed monoxide. ,− Between 2.0 and 2.5 Li/f.u. a further growth of the particles was not observed.…”

“…CoMn 2 O 4 , and CoFe 2 O 4 ,, spinels were reported as high-capacity anode materials, but Li uptake into CoMnFeO 4 has not been investigated, yet. CoMnFeO 4 was synthesized as thin films , and as powders for determination of the cation distribution and magnetic and catalytic properties. , Here we report for the first time on the electrochemical performance of CoMnFeO 4 nanoparticles as anode material. Furthermore, we investigate the reaction mechanism during Li insertion into the quaternary spinel by operando synchrotron-based XRD and XAS allowing monitoring the individual structural and electronic events occurring during the reaction.…”

“…CoMn 2 O 4 39,40 and CoFe 2 O 4 30,31,41 spinels were reported as high-capacity anode materials, but Li uptake into CoMnFeO 4 has not been investigated, yet. CoMnFeO 4 was synthesized as thin films 42,43 and as powders for determination of the cation distribution and magnetic and catalytic properties. 44,45 Here we report for the first time on the electrochemical performance of CoMnFeO 4 nanoparticles as anode material.…”