X-ray and neutron study on the structure of hydrous SiO glass up to 10 GPa

Urakawa, Satoru*; Inoue, Toru*; Hattori, Takanori; Sano, Asami; Kohara, Shinji*; Wakabayashi, Daisuke*; Sato, Tomoko*; Funamori, Nobumasa*; Funakoshi, Kenichi*

Minerals (Internet), 10(1), p.84_1 - 84_13, 2020/01

https://doi.org/10.3390/min10010084

The structure of hydrous amorphous SiO is fundamental to investigate the effects of water on the physicochemical properties of oxide glasses and magma. The hydrous SiO glass with 13 wt.% DO was synthesized under high-pressure and high-temperature conditions and its structure was investigated by small angle X-ray scattering, X-ray diffraction, and neutron diffraction experiments at pressures of up to 10 GPa and room temperature. This hydrous glass is separated into a SiO rich major phase and a DO rich minor phase. Medium-range order of the hydrous glass shrinks compared to the anhydrous SiO glass due to disruption of SiO linkage by formation of Si-OD deuterioxyl, while the pressure response is similar. Most of DO molecules are in the small domains and hardly penetrate into SiO major phase.

Local structure analysis of (NaKLi)NbO synthesized by malic acid complex solution method

Yoneda, Yasuhiro; Takada, Eri*; Nagai, Haruka*; Kikuchi, Takeyuki*; Morishita, Masao*; Kobune, Masafumi*

Japanese Journal of Applied Physics, 56(10S), p.10PB07_1 - 10PB07_7, 2017/10

https://doi.org/10.7567/JJAP.56.10PB07

A monoclinic phase was discovered in (NaKLi)NbO solid solution ceramics grown by a malic acid complex solution method. The average and local structures of this monoclinic phase were analyzed by synchrotron X-ray measurements. The local structure can be reproduced by assuming a rhombohedral model, that is the same local structure of KNbO. The results demonstrate that the monoclinic average structure is observed as a disordered rhombohedral structure.

Recent progress of line-profile analyses for neutron or X-ray diffraction

Tomota, Yo*; Sato, Shigeo*; Harjo, S.

Tetsu To Hagane, 103(2), p.73 - 85, 2017/01

https://doi.org/10.2355/tetsutohagane.TETSU-2016-085

Presence of -martensite as an intermediate phase during the strain-induced transformation of SUS304 stainless steel

Hatano, Masaharu*; Kubota, Yoshiki*; Shobu, Takahisa; Mori, Shigeo*

Philosophical Magazine Letters, 96(6), p.220 - 227, 2016/06

https://doi.org/10.1080/09500839.2016.1190876

We have investigated the formation process of '-martensite from the -phase induced by external strain using in-situ synchrotron diffraction experiments, combined with Lorentz transmission electron microscopy (TEM) and high-resolution TEM observations. It is clearly demonstrated that -martensite with hexagonal symmetry appears as an intermediate structure during the plastic deformation of SUS304 stainless steel. In addition to stacking faults and dislocations, interfaces between the twin structures presumably play a key role in the formation of -martensite.

Direct observation of lattice symmetry breaking at the hidden-order transition in URuSi

Tonegawa, Sho*; Kasahara, Shigeru*; Fukuda, Tatsuo; Sugimoto, Kunihisa*; Yasuda, Nobuhiro*; Tsuruhara, Yugo*; Watanabe, Daiki*; Mizukami, Yuta*; Haga, Yoshinori; Matsuda, Tatsuma*; et al.

Nature Communications (Internet), 5, p.4188_1 - 4188_7, 2014/06

https://doi.org/10.1038/ncomms5188

Structural changes in anatase TiO thin films irradiated with high-energy heavy ions

Ishikawa, Norito; Yamamoto, Shunya; Chimi, Yasuhiro

Nuclear Instruments and Methods in Physics Research B, 250(1-2), p.250 - 253, 2006/09

https://doi.org/10.1016/j.nimb.2006.04.119

Electronic excitation effects on TiO thin films with anatase structure irradiated with 230MeV Xe ions have been studied by means of X-ray diffraction method. X-ray diffraction intensity shows exponential decrease as a function of ion-fluence, indicating that tracks having about 10nm diameter are introduced by the irradiation. Rutile structured TiO was also irradiated and exhibited different damage behavior from that of anatase one. We demonstrated that X-ray diffraction meathod is one of the powerful tool to investigate track structure.

Pressure-temperature-time-transition diagram in a strong metallic supercooled liquid

Wang, W. H.*; Utsumi, Wataru; Wang, X. L.*

Europhysics Letters, 71(4), p.611 - 617, 2005/08

https://doi.org/10.1209/epl/i2005-10124-1

The crystallization kinetics and nucleation mechanism of a bulk metallic glassforming alloy ZrTiCuNiBe (vit4) in the entire supercooled liquid region (SLR) is investigated using in situ high-pressure and high-temperature X-ray diffraction with synchrotron radiation, which allows us for the time to simultaneously determine the crystallization kinetics and phase evolution of a metallic liquid as a function of time under high pressure. The results are summarized in a pressure-time-temperature-transformation (PTTT) diagram with two time scales.

The Disordered 3-dimensional structure visualized by a combination of high-energy synchrotron X-rays and computer simulations

Kohara, Shinji*; Oishi, Yasuo*; Takata, Masaki*; Yoneda, Yasuhiro; Suzuya, Kentaro

Nippon Kessho Gakkai-Shi, 47(2), p.123 - 129, 2005/04

https://doi.org/10.5940/jcrsj.47.123

The use of high-energy (E 50 keV) X-rays from SPring-8 allows us to perform X-ray diffraction experiments on disordered materials with the following advantages: high resolution in real space due to the wide range of scattering vector, small correction terms (particularly the absorption correction), and fast diffraction measurement with small amount of samples. Recently, high-energy X-ray diffraction data have been combined with neutron diffraction data from a pulsed neutron source to provide more detailed and reliable structural information than has hitherto been available. Furthermore, the use of reverse Monte Carlo modelling and PDF (pair distribution function) simulation based on high-energy X-ray diffraction data have succeeded in illustrating 3-dimensional structure of disordered materials and disorder in crystalline materials.

X-ray structural analysis of molten PbCl

Okamoto, Yoshihiro; Iwadate, Yasuhiko*; Fukushima, Kazuko*; Matsuura, Haruaki*; Minato, Kazuo

Journal of Physics and Chemistry of Solids, 66(2-4), p.452 - 455, 2005/02

https://doi.org/10.1016/j.jpcs.2004.06.039

The structure of molten PbCl was investigated by using X-ray diffrtaction(XRD) and X-ray absorption fine structure(XAFS) analysis techniques. From the fourier transformation analysis if the XRD data, the nearest Pb-Cl interaction consists of two kinds of interactions; rigid 4-fold tetrahedron and 2-3 loose coordination. The XAFS result shows a local structure is the 4-fold coordination in the melt.

Intermediate-range order in vitreous SiO and GeO

Kohara, Shinji*; Suzuya, Kentaro

Journal of Physics; Condensed Matter, 17(5), p.S77 - S86, 2005/02

https://doi.org/10.1088/0953-8984/17/5/009

The total structure factors, S(Q), obtained from high-energy X-ray and neutron diffraction measurements on vitreous SiO (v-SiO) and vitreous GeO (v-GeO) have been analysed by the reverse Monte Carlo (RMC) modelling technique to generate a three-dimensional structural model. The bond angle distributions and the ring size distributions from the model indicated that the sixfold ring and six- and sevenfold rings are dominant in v-SiO and v-GeO, respectively. However, the fraction of threefold rings of Ge in v-GeO is larger than that of Si in v-SiO glass. These features are consistent with the published neutron diffraction and Raman scattering studies.