Prediction of Influence of Oxygen in Annealing Atmosphere on Surface Segregation Behavior in Layered Materials

Abstract

It has often been observed that an element locating in an underlayer can segregate to the top surface of a layered structure. Whether in a vacuum or inert atmosphere, a method for predicting such segregation has been previously established. However, the annealing of a layered structure is sometimes carried out in an oxygen atmosphere. Therefore, the influence of oxygen in an annealing atmosphere upon the surface segregation behavior in layered materials is discussed here in. The energetics of oxygen adsorption onto each element within a layered material is considered. A formula for the prediction of surface segregation under an oxygen atmosphere is proposed. By introducing a general method to estimate the oxygen adsorption energy to metals and elemental semiconductors, some prediction examples are provided and are compared with experimental results.

Temperature and polarity dependence of electrical properties of ZnO film on pyroelectric LiNbO3single crystal

“…54,55) Based on the thermal diffusion theory with the metal/Li stack structure considering the oxygen vacancy formed interface, the adsorption energy of Zn (190 kJ mol −1 ) is between those of Mg (150 kJ mol −1 ) and Ti (232 kJ mol −1 ), meaning that Li can diffuse into ZnO as same as into MgO and TiO x . 56,57) The LN inversion layer should be formed near the interface by annealing at 900 °C. Furthermore, Li and Nb act as accepter and donor in ZnO, respectively.…”

(Invited) Development of New High-Dielectric Constant Thin Films By Combinatorial Synthesis

“…To reduce the leakage current and improve the temperature stability of dielectric constant, Ta was doped. Ta is able to reduce oxygen vacancies owing to its low oxidization energy, and inhibit the Bi migration in the BT-BMN layer at high temperature on the basis of the thermal diffusion theory (17)(18)(19). To investigate the Ta doping effects, a Ta composition spread sample was fabricated by combinatorial method as shown in Fig.…”

Combinatorial Thin Film Synthesis for Developments of New High Dielectric Constant Thin Film Materials

“…To reduce the leakage current and improve the temperature stability of dielectric constant, Ta was doped. Ta is able to reduce oxygen vacancies owing to its low oxidization energy, and inhibit the Bi migration in the BT-BMN layer at high temperature on the basis of the thermal diffusion theory [32][33][34]. To investigate the Ta doping effects, a Ta composition spread sample was fabricated by combinatorial method as shown in the inset of Fig.…”