Resonant PES at the Pr4d and Pr3d absorption edges is used to study the electronic properties at the interface of epitaxial grown Pr_2O_3 on Si(001). At the Si(001) interface in-situ prepared ...epitaxial layers (d < 5nm) enable us to study the contribution of the Pr4f electronic states in the valence band population as a function of layer thickness. We also find a silicate intermediate. In that range (1nm) the weak occupancy of the Pr4f states in the bulk phase of Pr_2O_3 is significantly enhanced. There is an additional 4f state which appears right at the VBM. On the other hand, in the XAS data we find the features of localized Pr4f states to be quenched. We conclude that the silicate causes an enhanced hybridization (covalent bonding) of the Pr4f states into the valence band. In our coverage dependent data the offset in the VB maxima is determined from the relative position of the valence band spectra. The offset of the conduction bands is deduced from the onset of the Si2p and Pr4d XAS data, it is of the order of 2eV again. Our data allow to derive a full description of the interface properties of that high K material, a prerequisite for its possible application in storage, logic, and power electronics.
碩士
國立高雄科技大學
化學工程與材料工程系
107
Polyphenylene oxide (PPO) was usually used in engineering plastics of IC tray, for this study, we use PPO's compatible property to blend with different carbon black, carbon ...fiber and glass fiber being a reinforcement material, and follow the standard of American Society for Testing Materials (ASTM) to test blending sample's physical properties. Sample pieces followed ASTM standard were injected from blending materials, and then study by tensile testing, bending test, percentage of elongation, shrinking, and used SEM to observe dispersibility of blending materials. The results show that CF/PPO is better than GF/PP and CB/PPO in rigidity, but the cost is higher than both of them and GF/PPO has good ductility and softness. CB/PPO is worse than both of CF/PPO and GF/PPO in physical properties, because it has a lower specific gravity, but its cost is lower than CF/PPO and GF/PPO, so CB/PPO is quite competitive in price.
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