The resistive switching mechanisms of ZrO 2 memory films are proposed to explain why resistive switching characteristics of Ti/ZrO 2 /Pt device are more stable than those of Pt/ZrO 2 /Pt and Al/ZrO 2 /Pt devices in this study. Different from the Pt/ZrO 2 /Pt and the Al/ZrO 2 /Pt devices, the carrier conduction mechanisms in the Ti/ZrO 2 /Pt device obey space charge limited current theory, which may be caused by the formation of the interface layer between Ti and ZrO 2 . Moreover, the resistive switching mechanisms are proposed to be related to the filament formation/rupture theory and oxygen ion migration. The location where filament formation/rupture takes place should be confined near the interface between Ti and ZrO 2 , leading to the stable resistive switching characteristics and a better endurance performance. During successive resistive cycles at room temperature and 150°C, the fatigue behaviors are observed due to the degradation of both two memory states, which might be related to the transformation of the interface layers between Ti and ZrO 2 and the coalescence of ZrO x clusters.

On account of their outstanding photo-luminescence properties, NV-(Nitrogen-vacancy) centers in diamond make possible the high-sensitivity detection of physical quantities. The concentration of NVcenters is one of the main factors that affect the sensitivity in detecting macroscopic physical quantities. This paper studied and analyzed the relationship between the dose of electron irradiation and the concentration of NVcenters. We found that after electron irradiation into diamond, luminescence centers of 524.7 nm, 541.1 nm, 578 nm and 648.1 nm were formed, which is necessary for producing NVcenters. After annealing at high temperature (≥ 800 ℃) and in vacuum (≥10-7 Pa) on diamond, NVcenters were formed when vacancies were bound by nitrogen atoms. We also obtained the rules of NVconcentration as a function of electron irradiation, which followed Boltzmann distribution. In addition, the number of NVproduced by electron injection was limited by 16 ppm for diamond with a nitrogen content of 100 ppm regardless of the increment of vacancies concentration. This study is the basis of quantitative preparation of NVcenters, and further lays a foundation for the application of NVcenters to the precise measurement of macroscopic physical qualities.