In recent years, due to the rapid development of electronic products, non-volatile memory has become more and more important. However, flash memory has faced some physical limits bottleneck with size scaling-down. In order to overcome this problem, alternative memory technologies have been extensively investigated, including ferroelectric random access memory (FeRAM), magneto resistive RAM (MRAM), phase-change RAM (PRAM), and resistive RAM (RRAM). All of this potential next generation non-volatile memory, the resistive random access memory has most advantages such as simple structure, lower consumption of energy, lower operating voltage, high operating speed, high storage time and non-destructive access, which make it be the most potential candidate of the next generation non-volatile memory. Many studies have proposed to explain the resistance switching phenomenon, which is due to the metallic filament or the oxygen vacancies. Therefore, in order to investigate the influence of resistance switching characteristic by metal or oxygen, we choose the non-metal contained boron oxy-nitride film as the insulator layer and successfully make the resistance has the switchable characteristic of this device. Furthermore, we improved the iv stability by using the Gadolinium-doped method in the boron oxy-nitride based film. In addition, we observed the negative current differential phenomenon during the set process, which can further controlled by lower operating voltage to achieve the interfacial resistance switching. We think that is due to the formation of nitrogen titanium oxide at the interface between insulator layer and titanium nitride electrode, which caused the Schottky barrier formation and reduced the current flow. In addition, current conduction fitting can also confirm this hypothesis. Besides, titanium nitride easily bond with oxygen ions; moreover, the oxygen ions can be easily disturbed at higher temperature ambient. We believed there may easily form the nitrogen titanium oxide layer in higher temperature environment; which also improve by a series of varied temperature experiments. However, this nitrogen titanium oxide layer formed naturally very easily, resulting in an inevitable problem of data retention time, which wish to be resolved in the future.

Office is a necessary workplace for corporate business operation in current commercial market, the maturity of office market development reflects the economy and commercial development status in different markets. The application of transacted office rental and vacancy rate as a primary data is relatively rare in pervious domestic literatures due to the difficultly of primary data collection. Therefore, the study of the correlation between office rental and vacancy rate by using primary data analysis is one of the research focus. Moreover, the lack of land supply for office development in Taipei CBD led to a rapid growth for suburban technology parks in the past decade. Corporate occupiers may relocate from the CBD to suburban technology parks due to competitive rental, improved public transportation network and information technology infrastructure. Therefore, the study of the correlation between suburban technology parks¡¦ office new supply and CBD Grade A office vacancy rate is another research focus in this thesis. The scope of study covers the Taipei CBD office submarkets and Neihu Technology Park and Nankang Software Park within suburban of Taipei City. The research method includes a literature review, market overview of CBD and suburban technology parks and empirical analysis of research data. By using correlation coefficient and ordinary least squares methods to analyze the factors, there are two finding revealed in the empirical results. Firstly, the empirical results revealed that the relationship between Taipei CBD Grade A office rental and vacancy rate is negative. Rental drop while vacancy increasing and oppositely rental increase while vacancy rate decline. The grade A rental may drop NT$27.16 per ping per month when Grade A vacancy rate increase 1%. Secondly, the empirical results revealed that the relationship between suburban technology parks¡¦ office new supply and CBD Grade A office vacancy rate is positive. The Grade A office vacancy rate may increase 1.53% when suburban technology parks increase 10,000 pings office new supply. NT$27.16 per ping per month when grade A vacancy rate increase 1%. It would be helpful for making business decisions on office leasing, real estate development and property investment if corporate occupiers, real estate developer and investor have more knowledge on office market vacancy rate and new supply information.

This experiment use NaCl (001) single crystal as substrate, and the target is zinc oxide, to generate a-plane (112 ¡Â0) zinc oxide nanothim. The nanofilm is used as a buffer layer generating by Ion Beam Sputtering, and then increasing the thickness by Plasma sputtering. Part of specimens to proceed atmospheric heat treatment with different temperature and time, and part of specimens to change the ratio of the gas when the thin film is growth, then use of Transmission electron microscopy (TEM) and Photoluminescence (PL) as the analysis of film properties. The results of experiment, show that (112 ¡Â0) plane have more stringent conditions when generate of thin film, and easy to become the ring of electron diffraction with no-epitaxy .But finally we get a data what can generate a well a-plane ZnO thin film, the substrate temperature of 400 ¢X C, the sputtering time of 1 hour, Ar/O2 = 1.5. From the results of Photoluminescence, we find that there are zinc vacancies in ZnO thin film, probably there are too many oxygen atoms. While the heat treatment in nitrogen, zinc vacancies are reduced rapidly. Indicating that oxygen atoms within the film are reduced by nitrogen atoms or replace the position of the oxygen atoms.

Non-stoichiometric barium titanate (BaTiO3) powder of TiO2-excess compositions has been investigated using both reducing sintering and acceptor-doping. Crystalline phases were analysed by XRD. Attention has been paid to the analysis of the corresponding sintered microstructure by adopting scanning and transmission electron microcopy. Reducing sintering was in the low oxygen partial pressure, so as to dominate the oxygen-deficient. According to the defect chemistry, the purpose of acceptor-doping was the same as reducing sintering. We look out for phenomena which may be indicative that oxygen vacancies generated by acceptor-doping and reducing sintering have resulted in the metastable retention of high temperature hexagonal-BaTiO3 to an ambient temperature. In the Mg-doped study investigated the possibility that Mg2+ substitutes on Ti4+ site rather than the Ba2+ site, as expected from the radii. According to the unknown phase was indexed a supercell of MgTiO3, that showed evidence of Mg2+ dissolves in BaTiO3 and occupies the Ba2+ site. To reduce in a hydrogen atmosphere was a high dark conductivity. The Ti3+ content was determined via colorimetry. Because of the defect chemistry led to oxygen-deficient h-BaTiO3, i.e.BaTi1-xTixO3-x/2. The observed volume expansion behavior under Ar-H2 atmosphere demonstrates the possibility of having various microstructures via control of oxygen partial pressure. The transformation matrix described the relation between the two reciprocal lattices of the twinning. Investigation of reciprocal lattices was shown that ordering oxygen deficient on the BaO3 layer in the twin boundary. There was evidence of XRD patterns and surface energy that explained more and more twins in the microstructure via control of the low oxygen partial pressure. According to this theory, lamellae twins were generated by oxygen-deficient. The hexagonal phase might be also expressed as the cubic BaTiO3 containing twin boundary at BaO3 planes every three layers. That demonstrates the possibility of hexagonal phase retention in BaTiO3 was oxygen vacancies.

The research work presented in this thesis comprises an electron microscopy and spectroscopy study of crystal defects that relate to the occurrence of different colours in natural and synthetic diamonds. Two principal lines of investigation have been covered, each with its own objective. The first aims to identify the source of brown colour in natural and synthetic diamond and the second to ascertain the distribution of colour inducing point defects in synthetic diamond. An outline of both areas of research is given below.1) Brown colour in natural and synthetic diamondsColour is a physical property that can be very difficult to characterise in diamond and consequently it receives regular attention from scientists working in the gem industry. In this work, the crystal structures of brown and colourless natural type IIa diamonds are compared along with brown coloured synthetic diamonds manufactured using the chemical vapour deposition (CVD) process. Numerous attempts have been made to trace the origin of brown tints in natural diamond, with the most likely sources, dislocations and nitrogen impurities, ruled out through the application of various analytical techniques. Recently more emphasis has been placed on the study of vacancy related defects in natural diamond and their influence on colour. Differences between the annealing characteristics of brown coloured natural and CVD diamonds suggest that the defect or defects responsible for the brown colour might be different for each type of diamond. The focus of this research work is the analysis of vacancy defects of the order of 1nm in size using aberration corrected scanning transmission electron microscopy (AC-STEM). The sub-nanometre size probe afforded by this technique allows such defect structures to be resolved much more readily than with conventional high resolution transmission electron microscopy (HR-TEM). Small-scale contrast variations are apparent in the lattice images of brown diamonds but not of the colourless variety. These features have been compared to simulated phase contrast images of vacancy clusters in diamond.2) Yellow / Green coloured synthetic diamonds grown using metal solvent catalystSynthetic diamonds for jewellery and industrial applications are routinely manufactured under high pressure-temperature (HPHT) conditions that closely resemble those found during the creation of natural diamonds. Although the manufacturing equipment can vary in design, the HPHT process that occurs inside the reaction vessel remains essentially the same. During processing, the carbon source material is dissolved into a molten metal and then precipitated onto tiny seed diamonds that are added to the reaction chamber. Much time and effort has been expended in refining this process to reduce impurities and defects in the finished diamonds. The presence of remnant transition metal atoms (e.g. nickel) in the crystal structure influences the electronic properties and in particular the colour of the diamonds. The position and configuration of these metallic defects has previously been studied by a variety of analytical techniques, including optical absorption-luminescence spectroscopy and electron paramagnetic resonance spectroscopy (EPR). These studies have proposed a number of optically active nickel centres at both substitutional and interstitial sites. Their association with vacancies and nitrogen atoms has also been highlighted. This work uses electron microscopy and spectroscopy to characterise the nickel defects in synthetic type 1b diamonds.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22465号 / 工博第4726号 / 新制||工||1738(附属図書館) / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 関 修平, 教授 水落 憲和, 准教授 菅瀬 謙治, 教授 梶 弘典 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(理学) / 甲第23459号 / 理博第4753号 / 新制||理||1681(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 倉田 博基, 教授 島川 祐一, 教授 寺西 利治 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

Quantum information technologies require networks of interacting defect bits. Color centers, especially the nitrogen vacancy (NV-) center in diamond, represent one promising avenue, toward the realisation of such devices. The most successful technique for creating NV- in diamond is ion implantation followed by annealing. Previous experiments have shown that shallow nitrogen implantation (<10 keV) results in NV- centers with a yield of 0.01%–0.1%. We investigate the influence of channeling effects during shallow implantation and statistical diffusion of vacancies using molecular dynamics and Monte Carlo simulation techniques. Energy barriers for the diffusion process were calculated using density functional theory. Our simulations show that 25% of the implanted nitrogens form a NV center, which is in good agreement with our experimental findings.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23388号 / 工博第4880号 / 新制||工||1763(附属図書館) / 京都大学大学院工学研究科材料化学専攻 / (主査)教授 三浦 清貴, 教授 田中 勝久, 教授 藤田 晃司 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

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