Mn–Co–Ni–O thin films prepared by sputtering with alloy target

The thin film of heat-sensitive materials has been widely concerned with the current trend of miniaturization and integration of sensors.In this work,Mn1.56 Co0.96 Ni0.48 O4(MCNO)thin films were prepared on Si O2/Si substrates by sputtering with Mn–Co–Ni alloy target and then annealing in air at different temperatures(650–900℃).The X-ray diffraction(XRD)and field emission scanning electron microscopy(FE-SEM)analysis indicated that the main crystalline phase of MCNO thin films was spinel crystal structure;the surface of the thin films was very dense and uniform.The electrical properties of the thin films were studied in the temperature range of–5–50℃.The MCNO thin film with a low room temperature resistance R25 of 71.1 kΩand a high thermosensitive constant B value of 3305 K was obtained at 750℃.X-ray photoelectron spectroscopy(XPS)analysis showed that the concentration of Mn3+and Mn4+cations in MCNO thin films is the highest when annealing temperature is 750℃.The complex impedance analysis revealed internal conduction mechanism of the MCNO thin film and the resistance of the thin film was dominated by grain boundary resistance.

Mn-Co-Ni-O thin films prepared by sputtering with alloy target