Distribution Of Lattice Spacing Research Articles

Monitoring the temperature of reactor experiments using radiation-induced swelling in SiC

Temperature monitoring of reactor experiments is an important quality requirement. High-purity silicon carbide (SiC) can be used to provide such data through post-irradiation material analysis. This method stems from radiation defect concentrations’ dependence on irradiation temperature. Irradiation temperature can be determined by measuring irradiation-induced property changes, for example lattice spacing distribution, dimensions, electrical resistivity, etc.—after isochronal annealing. Such methods are time-consuming, since multiple steps must be performed in a serial manner. We investigated the possibility of using an alternative method that does not require multiple heat treatments. Instead, peak irradiation temperature is determined by a calibration curve comparing pre- and post-irradiation sample dimensions. The experimental results demonstrate the feasibility of this approach in the irradiation conditions described below. This approach can also be used to measuring changes in other properties mentioned above.

Lattice spacing distribution at Pd/Ag(111) interface by transmission electron microscopy

Lattice spacing distribution at Pd/Ag(111) interface by transmission electron microscopy

Uniformity Evaluation of Lattice Spacing of 28Si Single Crystals

The uniformity of the lattice spacing of silicon crystals was evaluated by the self-referenced lattice comparator with a resolution of $3\times 10^{\mathrm {\mathbf {-9}}}$ . Lattice strain measurements were performed for the sample 10.5 cut from 28Si ingot (Avo28), which was used to determine the Avogadro constant. The mapping results for samples 4.R1, XINT, and 9.R1 performed in the previous works have also been re-evaluated. The 4.R1 in the seed side of the ingot and the XINT in the middle of the ingot have small distribution of lattice spacing. The standard deviations of the lattice spacing distribution for the 4.R1 and XINT were $4.8\times 10^{\mathrm {\mathbf {-9}}}$ and $5.5\times 10^{\mathrm {\mathbf {-9}}}$ , respectively. In contrast, the 9.R1 and the 10.5 samples cut from the tail side of the ingot have a larger distribution of lattice spacing. These lattice spacing distributions in the ingot are consistent with the impurity distribution in the ingot.

STEM Moiré Observation of Lattice-Relaxed Germanium Grown on Silicon

We deposited Ge films on Si substrates by molecular beam epitaxy (MBE) method. The specimens were annealed at around 750 C using microwave- plasma heating technique which we had reported before. After these pro- cesses, we carried out special scanning transmission electron microscopic (STEM) observation. The moire between the crystal lattices and the scanning lines controlled by STEM was utilized to show lattice-spacing distribution. The results exhibited that we were succeeded in forming lattice-relaxed Ge thin films. It was also recognized that this STEM moire technique is very useful to observe lattice-spacing distribution for large area with high resolution.

Homogeneity Characterization of Lattice Spacing of Silicon Single Crystals

The homogeneity of the lattice spacing of silicon single crystals was investigated by a self-referenced lattice comparator. Strain measurements were performed on single crystals from an $^{28}$ Si ingot (Avo28), which was used to determine the Avogadro constant. A swirl pattern was observed for sample 9.R1 cut from the tail side of the Avo28 ingot. The lattice spacing distribution of seed-side sample 4.R1 was smooth and homogeneous. The lattice spacing distribution was larger for the sample with higher impurities of carbon and oxygen.

TEM analysis of nanometer-size surface structures formed by bias enhanced nucleation of diamond on iridium

Bias enhanced nucleation of diamond on Ir/SrTiO 3(0 0 1) substrates usually causes a characteristic roughening of the Ir surface. On top of this, small particles with typical dimensions between 5 and 10 nm are found. Different microscopy techniques (atomic force microscopy, scanning electron microscopy, and transmission electron microscopy) were used in order to study the structure of these particles and determine their role in the diamond nucleation process. The nanoparticles are found laying loosely on the Ir surface: either equally dispersed or in clusters. After an additional short growth step, they can also be observed on top of the diamond grains. High-resolution transmission electron microscopy micrographs reveal a lattice constant that is close to that of Ir. Similar particles were observed on the nucleation side of thick delaminated diamond films after a growth process of several days. In contrast to the findings on top of the Ir surface, these nanoparticles are sometimes well aligned to the diamond film and show a wide distribution of lattice spacing. All results of the present study concurrently question any crucial role of the nanoparticles in the diamond nucleation process on iridium.

Relationship between Self-Texture and Interfacial Restriction on the Epitaxy of ZNO Thinfilms I

ABSTRACTWe investigated relationships between self-texture and interfacial restriction on the epitaxy of directed, bonded, thin films. Defect structures in ZnO films grown epitaxially on (0001)sapphire mere evaluated by 3—dimensional maping of k—spacing using an X—ray double crystal spectrometer. The orientation distribution and variation in lattice spacing of the films wre individually measured to elucidate the mechanism of growth. The growth mode was found to change at a film thickness of approximately 100 Å. The layer within 100Å of the interface had a small orientation distribution (1.8'), a large lattice spacing distribution, and a large cumpressive stress.The layer that was more than 100Å from the interface had a larger orientation distribution, a smaller lattice spacing distribution, and a smaller compressive stress.