A number of zinc oxide（Zn O） films are deposited on silicon substrates using the magnetron sputtering method.After undergoing thermal treatment under different conditions, those films exhibit hexagonal wurtzite structures and different photoluminescent characteristics. Besides the notable ultraviolet emission, which is related to the free exciton effect, a distinct blue fluorescence around 475 nm is found in some special samples.The blue photoluminescence emission of the Zn O film is believed to be caused by oxygen vacancies.
We prepare Si x （ZrO 2 ） 100 x composite films using the co-sputtering method. The chemical structures of the films which are prepared under different conditions are analyzed with X-ray photoemission spectroscopy. Thermal treatment influences on optical property and resistance switching characteristics of these composite films are investigated by spectroscopic ellipsometry and semiconductor parameter ana- lyzer, respectively. With the proper Si-doped Si x （ZrO 2） 100 x interlayer, the Al/ Si x （ZrO 2 ） 100 x /Al device cell samples present very reliable and reproducible switching behaviors. It provides a feasible solution for easy multilevel storage and better fault tolerance in nonvolatile memory application.
The mechanism of ferromagnetic ordering in ZrOx film is investigated by both experimental observation and theoretical calculation.Magnetic measurements reveal that the magnetic properties can be adjusted from diamagnetism to ferromagnetism by varying the oxygen stoichiometry.We find that oxygen-rich defects can be responsible for the observed magnetic properties by taking the measurements of x-ray photoelectron spectroscopy and room temperature photoluminescence spectra.Density functional theory calculations further confirm that the ferromagnetic order is mainly driven by the exchange interaction between the oxygen antisites and the neighboring anion atoms.
