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森 悠一郎*; 鍵 裕之*; 青木 勝敏*; 高野 将大*; 柿澤 翔*; 佐野 亜沙美; 舟越 賢一*
Earth and Planetary Science Letters, 634, p.118673_1 - 118673_8, 2024/05
水素による鉄の体積膨張に対するケイ素の効果を調べるため、高圧高温下でのhcp-Fe
Si
の中性子回折実験とX線回折実験を行った。中性子回折実験は重水素化hcp-FeSiに対して13.5GPa, 900K及び12.1GPa, 300Kで行い、得られたプロファイルからリートベルト解析を用いて水素占有率を決定した。hcp-Fe-SiのP-V-T状態方程式を組み合わせることにより、hcp-FeSiの水素による体積膨張が純粋なhcp鉄の体積膨張よりも10%大きいことを示した。得られた値を用いて、内核の密度欠損を再現できる水素量を見積もったところ、シリコンの影響がない場合に比べて50%減少した。hcp-FeSiで内核の密度欠損を再現した場合、内核と外核で可能な水素量xはそれぞれ0.07と0.12-0.15と計算された。
O/HO vapor generator for contrast-variation neutron scattering有馬 寛*; 高田 慎一; 笠井 聡*; 大内 啓一*; 森川 利明*; 宮田 登*; 宮崎 司*; 青木 裕之; 岩瀬 裕希*; 廣井 孝介; et al.
Journal of Applied Crystallography, 56(6), p.1802 - 1812, 2023/12
被引用回数：0 パーセンタイル：0.02(Chemistry, Multidisciplinary)The contrast-variation technique in neutron scattering experiments plays a pivotal role in distinguishing partial structures within multi-component complexes, facilitating the elucidation of distinct sample constituents. This differentiation is achieved using different isotopes, namely hydrogen and deuterium, which possess varying neutron scattering characteristics. This study presents a novel vapor generator designed for neutron scattering experiments, enabling continuous control of the DO/HO ratio of the vapor. This feature is especially useful for contrast-variation studies. The generator features two saturators and four mass flow controllers, allowing for the rapid and independent generation of DO/HO vapors. Additionally, the incorporation of the two-temperature method ensures accurate dew point control within a margin of 
0.2
Cdp. This setup proves useful for conducting time-resolved experiments and can accelerate research on functional polymers, such as polymer electrolyte membranes for fuel cells, where water potential assumes critical importance.
筋田 涼太*; 今井 彩帆里*; 大内 誠*; 青木 裕之; 寺島 崇矢*
Macromolecules, 56(23), p.9738 - 9749, 2023/12
被引用回数：0 パーセンタイル：0(Polymer Science)Constructing ordered ionic nanostructures into bulk polymers and thin films is an important technique to create functional materials, such as polyelectrolytes and proton- and ion-conducting materials, for various applications. Herein, we report microphase separation of cationic homopolymers bearing alkyl ammonium bromides to create sub-4 nm lamellar materials, where an ionic phase is alternatingly layered with a hydrophobic alkyl phase and serves as a channel for water intercalation. We prepared cationic homopolymers with linear or branched alkyl pendants (octyl or 2-ethylhexyl group: C8-eicosyl or 2-octyldodecyl group: C20) via the free radical polymerization of 2-(dimethylamino)ethyl acrylate (DMAEA), followed by the quaternization of the polyDMAEA with corresponding alkyl bromides. The homopolymers carrying linear hexadecyl, octadecyl, and eicosyl groups were crystalline at room temperature, whereas the others were amorphous. The homopolymers bearing linear alkyl pendants longer than the decyl group or branched alkyl pendants larger than the 2-butyloctyl group formed lamellar structures by the self-assembly of the side chains. The domain spacing can be controlled between 2.5 and 3.7 nm by tuning the pendant structures and are smaller than that formed by the corresponding random copolymers. A cationic homopolymer bearing crystalline octadecyl groups maintained lamellar structures up to 
210 
C far beyond the melting temperature (50 C). The cationic homopolymer further formed a multilayered lamellar thin film on a silicon substrate, in which the cationic layers absorbed water under humid conditions and reversibly released the water therefrom in a N gas atmosphere.
橋本 慧*; 塩飽 透*; 青木 裕之; 横山 英明*; 眞弓 皓一*; 伊藤 耕三*
Science Advances (Internet), 9(47), p.eadi8505_1 - eadi8505_8, 2023/11
被引用回数：5 パーセンタイル：45.8(Multidisciplinary Sciences)The demand for mechanically robust polymer-based electrolytes is increasing for applications to wearable devices. Young's modulus and breaking energy are essential parameters for describing the mechanical reliability of electrolytes. The former plays a vital role in suppressing the short circuit during charge-discharge, while the latter indicates crack propagation resistance. However, polymer electrolytes with high Young's moduli are generally brittle. In this study, a tough slide-ring solid polymer electrolyte (SR-SPE) breaking through this trade-off between stiffness and toughness is designed on the basis of strain-induced crystallization (SIC) and phase separation. SIC makes the material highly tough (breaking energy, 80 to 100 megajoules per cubic meter). Phase separation in the polymer enhanced stiffness (Young's modulus, 10 to 70 megapascals). The combined effect of phase separation and SIC made SR-SPE tough and stiff, while these mechanisms do not impair ionic conductivity. This SIC strategy could be combined with other toughening mechanisms to design tough polymer gel materials.
Liu, Y.*; 宮田 登*; 宮崎 司*; 春藤 淳臣*; 川口 大輔*; 田中 敬二*; 青木 裕之
Langmuir, 39(29), p.10154 - 10162, 2023/06
被引用回数：1 パーセンタイル：45.8(Chemistry, Multidisciplinary)Water absorbed by epoxy resins from a humid atmosphere considerably influences their structure and properties. Examining the effects of absorbed water on epoxy resins at their interfaces with solid substrates is crucial because of their adhesive applications in various fields. The spatial distribution of absorbed water in epoxy resin thin films under high humidity was investigated in this study by neutron reflectometry. Water molecules were found to accumulate at the SiO
/epoxy resin interface after exposure at a relative humidity of 85% for 8 h. The formation of an ca.1 nm-thick condensed water layer was observed, and the thickness of this layer varied with curing conditions of epoxy systems. Furthermore, the water accumulation at the interface was noted to be affected by high-temperature and high-humidity environments. The formation of the condensed water layer is presumed to be related to the features of the polymer layer near the interface. The construction of the interface layer of epoxy resin would be affected by the interface constraint effect on the cross-linked polymer chain during the curing reaction. This study provides essential information for understanding the factors influencing the accumulation of water at the interface in epoxy resins. In the practical application, the process of improving the construction of epoxy resin near the interface would be a reasonable solution to resist the water accumulation in the interface.
Ni
D
at high 
conditions市東 力*; 鍵 裕之*; 柿澤 翔*; 青木 勝敏*; 小松 一生*; 飯塚 理子*; 阿部 淳*; 齋藤 寛之*; 佐野 亜沙美; 服部 高典
American Mineralogist, 108(4), p.659 - 666, 2023/04
被引用回数：1 パーセンタイル：59.64(Geochemistry & Geophysics)FeNiH(D)の12GPa, 1000Kまでの高温高圧下における相関係と結晶構造をその場X線及び中性子回折測定により明らかにした。今回実験した温度圧力下において、FeNiH(D)ではFeH(D)とは異なり、重水素原子は面心立方構造(fcc)中の四面体サイトを占有しないことが明らかになった。単位重水素あたりの水素誘起膨張体積
は、fcc相で2.45(4) 
、hcp相で3.31(6) であり、FeDにおけるそれぞれの値より著しく大きいことが明らかになった。また、は温度の上昇に伴いわずかに増加した。この結果は、鉄に10%ニッケルを添加するだけで、金属中の水素の挙動が劇的に変化することを示唆している。が圧力に関係なく一定であると仮定すると、地球内核の最大水素含有量は海洋の水素量の1-2倍であると推定される。
Hibino, Masayuki*; 高田 慎一; 廣井 孝介; 青木 裕之; 寺島 崇矢*
Macromolecules, 56(8), p.2955 - 2964, 2023/04
被引用回数：0 パーセンタイル：0(Polymer Science)Amphiphilic random copolymers bearing poly(ethylene glycol) (PEG) and alkyl groups as side chains are intermolecularly self-assembled into size-controlled multichain micelles in water. The random copolymer micelles are known to induce the exchange of their polymer chains, whereas the details of the kinetics and mechanism have not been elucidated yet. Herein, we investigated the exchange kinetics and mechanism of the random copolymer chains between their micelles by time-resolved small-angle neutron scattering (TR-SANS). For this purpose, random copolymers carrying PEG and deuterated butyl or dodecyl groups were designed for deuterated micelles. After mixing deuterated and non-deuterated micelle solutions, the resulting mixtures were monitored by TR-SANS at various concentrations and temperatures. The scattering intensity of the micelle mixtures decayed with time, indicating that deuterated copolymers were gradually mixed with non-deuterated copolymers via chain exchange between their micelles to form micelles consisting of both deuterated and non-deuterated copolymers. The kinetic analysis revealed that the exchange of their polymer chains involved two mechanisms: A unimer release and insertion pathway was dominant in diluted conditions, whereas the contribution of a micelle collision pathway increased with increasing total polymer concentration and temperature. The activation energy of the polymer exchange process was dependent on the hydrophobic alkyl groups and larger than that of a related surfactant micelle.
下北 啓輔*; 山本 勝宏*; 宮田 登*; 中西 洋平*; 柴田 基樹*; 竹中 幹人*; 山田 悟史*; 瀬戸 秀樹*; 青木 裕之; 宮崎 司*
Soft Matter, 19(11), p.2082 - 2089, 2023/03
被引用回数：0 パーセンタイル：0(Chemistry, Physical)In the case of poly(methyl methacrylate) (PMMA) thin films on a Si substrate, thermal annealing induces the formation of a layer of PMMA chains tightly adsorbed near the substrate interface, and the strongly adsorbed PMMA remains on the substrate, even after washing with toluene (hereinafter called adsorbed sample). Neutron reflectometry revealed that the concerned structure consists of three layers: an inner layer (tightly bound on the substrate), a middle layer (bulk-like), and an outer layer (surface) in the adsorbed sample. When an adsorbed sample was exposed to toluene vapor, it became clear that, between the solid adsorption layer (which does not swell) and bulk-like swollen layer, there was a "buffer layer" that could sorb more toluene molecules than the bulk-like layer. This buffer layer was found not only in the adsorbed sample but also in the standard spin-cast PMMA thin films on the substrate. When the polymer chains were firmly adsorbed and immobilized on the Si substrate, the freedom of the possible structure right next to the tightly bound layer was reduced, which restricted the relaxation of the conformation of the polymer chain strongly. The "buffer layer" was manifested by the sorption of toluene with different scattering length density contrasts.
吉宗 航*; Kikkawa, Nobuaki*; Yoneyama, Hiroaki*; Takahashi, Naoko*; Minami, Saori*; Akimoto, Yusuke*; Mitsuoka, Takuya*; Kawaura, Hiroyuki*; Harada, Masashi*; 山田 悟史*; et al.
ACS Applied Materials & Interfaces, 14(48), p.53744 - 53754, 2022/11
被引用回数：7 パーセンタイル：63.54(Nanoscience & Nanotechnology)Chemically modified carbon supports for the cathode catalyst layers of polymer electrolyte fuel cells (PEFCs) show considerable promise for boosting the oxygen reduction reaction. This study evaluated the ionomer distribution of Nafion ionomer thin films on nitrogen (N)-modified carbon surfaces along their depth direction. Neutron reflectivity (NR) measurements performed using the double-contrast technique with HO and DO revealed that the introduction of N functional groups to carbon thin films promoted ionomer adsorption onto the surface under wet conditions (22C, 85% relative humidity). Molecular dynamics (MD) simulations conducted to verify the origin of the robust contact between the ionomer and N-modified carbon surface revealed an ionomer adsorption mechanism on the N-modified carbon surfaces, which involved Coulomb interactions between the positively charged carbon surface and the ionomer side chains with negatively charged sulfonic acid groups. The positive surface charge, which was determined using the contents of the N functional groups estimated by X-ray photoelectron spectroscopy, was found to be sufficient as an impetus for ionomer adsorption. This strategy involving NR measurements and MD simulations can provide insights into the solid-ionomer interfacial structures in a cathode catalyst layer and can therefore be extensively employed in studies on PEFCs.
下北 啓輔*; 山本 勝宏*; 宮田 登*; 有馬 寛*; 中西 洋平*; 竹中 幹人*; 柴田 基樹*; 山田 悟史*; 瀬戸 秀樹*; 青木 裕之; et al.
Langmuir, 38(41), p.12457 - 12465, 2022/10
被引用回数：0 パーセンタイル：0(Chemistry, Multidisciplinary)We measured the neutron reflectivity (NR) of isotactic polypropylene (PP) thin films deposited on Si substrates modified by hexamethyldisilazane (HMDS) at the saturated vapor pressure of deuterated water at 25C and 60C/85% RH to investigate the effect of HMDS on the interfacial water accumulation in PP-based polymer/inorganic filler nanocomposites and metal/resin bonding materials. We found that the amount of water accumulated at the PP/Si interface decreased with increasing immersion time of the Si substrate in a solution of HMDS in hexane prior to PP film deposition. During the immersion of the Si substrate, the HMDS molecules were deposited on the Si substrate as a monolayer without aggregation. Furthermore, the coverage of the HMDS monolayer on the Si substrate increased with increasing immersion time. At 60C and 85% RH, only a slight amount of interfacial water was detected after HMDS treatment for 1200 min. As a result, the maximum concentration of interfacial water was reduced to 0.1 from 0.3, where the latter corresponds to the PP film deposited on the untreated substrate.
今井 彩帆里*; 荒川 勝利*; 中西 洋平*; 竹中 幹人*; 青木 裕之; 大内 誠*; 寺島 崇矢*
Macromolecules, 55(20), p.9113 - 9125, 2022/10
被引用回数：3 パーセンタイル：24.75(Polymer Science)Microphase separation of copolymers is a key technique to produce polymer bulk materials or thin films with ordered nanostructures for applications in various research fields including nanotechnologies, electronic devices, among many others. Herein, we report water-assisted microphase separation of amphiphilic random copolymers bearing quaternary ammonium cations and hydrophobic alkyl or oleyl groups in the solid state and the thin films. We investigated the effects of sample preparation protocols and the hydrophobic pendants (a butyl group: C4 - octadecyl or oleyl group: C18), composition, and molecular weight of the copolymers on the microphase separation behavior. By annealing under humid conditions, the copolymers bearing alkyl groups longer than an octyl group (C8) formed sub-5 nm lamellar structures comprising cationic layers and hydrophobic layers. Water hardly remained in the resulting lamellar materials under ambient conditions. The domain spacing was controlled between 3.7 and 5.3 nm by tuning the length of the hydrophobic pendants and composition and was independent of the molecular weight and molecular weight distribution. The cationic random copolymers carrying amorphous hydrophobic pendants provided transparent or translucent polymer materials containing small lamellar structures. The random copolymers further formed multilayered lamellar thin films on silicon substrates by spin-coating the copolymer solutions, followed by a humid annealing process. The layered lamellae were directly observed as terrace structures with about 4-5 nm steps by atomic force microscopy.
Yamaguchi, Ko*; 川口 大輔*; 宮田 登*; 宮崎 司*; 青木 裕之; Yamamoto, Satoru*; 田中 敬二*
Physical Chemistry Chemical Physics, 24(36), p.21578 - 21582, 2022/09
被引用回数：5 パーセンタイル：67.52(Chemistry, Physical)A better understanding of the chemical reaction between epoxy and amine compounds at a solid interface is crucial for the design and fabrication of materials with appropriate adhesive strength. Here, we examined the curing reaction kinetics of epoxy phenol novolac and 4,4'-diaminodiphenyl sulfone at the outermost interface using sum-frequency generation spectroscopy, and X-ray and neutron reflectivity in conjunction with a full atomistic molecular dynamics simulation. The reaction rate constant was much larger at the quartz interface than in the bulk. While the apparent activation energy at the quartz interface obtained from an Arrhenius plot was almost identical to the bulk value, the frequency factor at the quartz interface was greater than that in the bulk. These results could be explained in terms of the densification and orientation of reactants at the interface, facilitating the encounter of the reactants present.
structural analysis of an aligning agent additive for the alignment of nematic liquid crystals on solid substrates根本 文也*; 山田 悟史*; 日野 正裕*; 青木 裕之; 瀬戸 秀樹*
Soft Matter, 18(3), p.545 - 553, 2022/01
被引用回数：0 パーセンタイル：0(Chemistry, Physical)Surface aligning agents, such as amphiphilic surfactants, are widely used to control the initial alignment of nematic liquid crystals (NLCs) in liquid crystal displays (LCDs). Generally, these agents are first coated on a substrate prior to NLC introduction. When mixed with NLCs, long alkyl chain amphiphilic agent additives may control the NLC alignment without requiring pretreatment because they may spontaneously form an adsorbed layer at the solid-NLC interface. These self-assembled layers (SALs) appear promising in the effective control of the initial alignment of LCDs. However, direct observation of the adsorbed layer structure in contact with the NLCs is challenging due to probe limitations. Furthermore, the areal densities and alignments of the amphiphiles adsorbed from NLCs at the solid-NLC interface are not previously reported. Herein, the structure of the surface aligning agent 
-hexadecyltrimethylammonium-d
bromide (d-CTAB) was investigated at the silicon-NLC interface using neutron reflectometry (NR), which indicated that the CTAB self-assembled as a monolayer, with its alignment dependent on the amphiphile concentration. At low amphiphile concentrations, the alignment of the SAL and NLCs was parallel to the substrate. With increasing amphiphile concentration, the number of amphiphiles attached to the substrate increased within the framework of the Gibbs monolayer, with the alignment of the amphiphiles and NLCs becoming perpendicular to the substrate. The experimental setup used here is comparable to those of more natural systems, such as those found in the alignment of NLCs in LCDs.
Ikami, Takaya*; Watanabe, Yuki*; 小川 紘輝*; 竹中 幹人*; 山田 悟史*; 大内 誠*; 青木 裕之; 寺島 崇矢*
ACS Macro Lett (Internet), 10(12), p.1524 - 1528, 2021/12
被引用回数：8 パーセンタイル：46.56(Polymer Science)Making ordered nanostructures in polymers and their thin films is an important technique to produce functional materials. Herein, we report instant yet precise self-assembly systems of amphiphilic random copolymers to build multilayered lamellar structures in bulk materials and thin films. Random copolymers bearing octadecyl groups and hydroxyethyl groups induced crystallization-driven microphase separation via simple evaporation from the solutions to form lamellar structures in the solid state. The domain spacing was controlled in the range between 3.1 and 4.2 nm at the 0.1 nm level by tuning copolymer composition. Interestingly, just by spin-coating the polymer solutions onto silicon substrates, the copolymers autonomously formed thin films consisting of multilayered lamellar structures, where amorphous/hydrophilic parts and crystalline octadecyl domains are alternatingly layered from a silicon substrate to the air/polymer interface at regular intervals. The lamellar domain spacing was tunable by selecting hydrophilic pendants.
和泉 篤士*; 首藤 靖幸*; 柴山 充弘*; 宮田 登*; 宮崎 司*; 青木 裕之
Langmuir, 37(47), p.13867 - 13872, 2021/11
被引用回数：2 パーセンタイル：14.19(Chemistry, Multidisciplinary)The structural formation mechanism of phenolic resin-silica interfaces was investigated in situ by neutron reflectometry during curing. There was a 4 nm thick novolac resin adsorption layer on the silica surface before curing. The curing reaction of the novolac resin with hexamethylenetetramine (HMTA) increased the coherent neutron scattering length density of the resin due to the cure shrinkage accompanied by the volatilization of ammonia, which is a byproduct of HMTA decomposition. As curing proceeded at 180C, the thickness of the bulk layer increased despite the cure shrinkage, and the thickness of the interfacial layer decreased from 4 to 1 nm. This is attributed to the diffusion of decomposed HMTA fragments generated in the bulk layer into the interfacial novolac adsorption layer during diffusion throughout the bulk layer, incorporating the upper part of the interfacial layer reacting with the fragment into the bulk layer. On the other hand, the fragments could not diffuse into the tightly bound immobile segments of novolac resin in direct contact with the silica surface, retaining the 1-2 nm thick interfacial layer in the cured resin. This structural formation mechanism caused interfacial cross-link inhomogeneity in the cured resin on the silica surface.
大塚 悠介*; 金澤 直也*; 平山 元昭*; 松井 彬*; 野本 拓也*; 有田 亮太郎*; 中島 多朗*; 花島 隆泰*; Ukleev, V.*; 青木 裕之; et al.
Science Advances (Internet), 7(47), p.eabj0498_1 - eabj0498_9, 2021/11
被引用回数：8 パーセンタイル：51.2(Multidisciplinary Sciences)FeSi is a nonmagnetic narrow-gap insulator, exhibiting peculiar charge and spin dynamics beyond a simple band structure picture. Those unusual features have been attracting renewed attention from topological aspects. Although the surface conduction was demonstrated according to size-dependent resistivity in bulk crystals, its topological characteristics and consequent electromagnetic responses remain elusive. Here, we demonstrate an inherent surface ferromagnetic-metal state of FeSi thin films and its strong spin-orbit coupling (SOC) properties through multiple characterizations of two-dimensional conductance, magnetization, and spintronic functionality. Terminated covalent bonding orbitals constitute the polar surface state with momentum-dependent spin textures due to Rashba-type spin splitting, as corroborated by unidirectional magnetoresistance measurements and first-principles calculations. As a consequence of the spin-momentum locking, nonequilibrium spin accumulation causes magnetization switching. These surface properties are closely related to the Zak phase of the bulk band topology. Our findings propose another route to explore noble metal-free materials for SOC-based spin manipulation.
青木 裕之; Liu, Y.*; 山下 貴志*
Scientific Reports (Internet), 11(1), p.22711_1 - 22711_9, 2021/11
被引用回数：9 パーセンタイル：60.44(Multidisciplinary Sciences)Neutron reflectometry (NR) allows us to probe into the structure of the surfaces and interfaces of various materials such as soft matters and magnetic thin films with a contrast mechanism dependent on isotopic and magnetic states. The neutron beam flux is relatively low compared to that of other sources such as synchrotron radiation; therefore, there has been a strong limitation in the time-resolved measurement and further advanced experiments such as surface imaging. This study aims at the development of a methodology to enable the structural analysis by the NR data with a large statistical error acquired in a short measurement time. The neural network-based method predicts the true NR profile from the data with a 20-fold lower signal compared to that obtained under the conventional measurement condition. This indicates that the acquisition time in the NR measurement can be reduced by more than one order of magnitude. The current method will help achieve remarkable improvement in temporally and spatially resolved NR methods to gain further insight into the surface and interfaces of materials.
丸山 龍治; 山崎 大; 青木 裕之; 阿久津 和宏*; 花島 隆泰*; 宮田 登*; 曽山 和彦; Bigault, T.*; Saerbeck, T.*; Courtois, P.*
Journal of Applied Physics, 130(8), p.083904_1 - 083904_10, 2021/08
被引用回数：3 パーセンタイル：26.56(Physics, Applied)Ferromagnetic (FM) interlayer exchange coupling of ion-beam sputtered Fe/Ge multilayers was investigated by off-specular polarized neutron scattering measurements. We observed a monotonously growing correlation of magnetic moments in the out-of-plane direction with decreasing Ge thickness. The results of the Fe/Ge multilayers were used to invoke FM interlayer exchange coupling in a neutron polarizing supermirror in order to extend its bandwidth. Typically, the bandwidth is limited due to a Curie temperature close to room temperature of the thinnest Fe layers with less than 3 nm. We propose a modified layer sequence of the neutron polarizing supermirror, where the minimum Fe thickness was set to 3.5 nm whereas the Ge thickness was reduced. A performance test of the neutron polarizing supermirror showed that the FM interlayer exchange coupling contributed to the presence of the magnetization comparable to the bulk and resulted in a marked extension in the bandwidth.
宮崎 司*; 宮田 登*; 有馬 寛*; 吉良 弘*; 大内 啓一*; 笠井 聡*; 津村 佳弘*; 青木 裕之
Langmuir, 37(32), p.9873 - 9882, 2021/08
被引用回数：5 パーセンタイル：36.83(Chemistry, Multidisciplinary)We investigated the structure of the crystalline adsorption layer of poly(vinyl alcohol) (PVA) in hot water by neutron reflectivity in two cases: when the adsorption layer is exposed on the substrate by leaching the upper bulk layer and when it is deeply embedded between a relatively thick PVA film and substrate. In both cases, the PVA adsorption layer consists of three layers on the Si substrate. The bottom layer, consisting of amorphous chains that are strongly constrained on the substrate, is not swollen even in hot water at 90C. The middle layer, consisting of amorphous chains that are much more mobile compared with those in the bottom layer, has no freedom to assume a crystalline form. Only the molecular chains in the top layer are crystallizable in the adsorption layer, leading to a heterogeneous layered structure in the film thickness direction. This layered structure is attributed to the crystallizable chains of PVA during the formation of the adsorption layer driven by hydrogen bonding. However, the structure and dynamics in the adsorption layer may differ in both cases because the molecular chains in the vicinity of the surface seem to be affected by surface effects even in the adsorption layer.
丸山 龍治; 山崎 大; 阿久津 和宏*; 花島 隆泰*; 宮田 登*; 青木 裕之; 曽山 和彦
JPS Conference Proceedings (Internet), 33, p.011092_1 - 011092_6, 2021/03
中性子偏極スーパーミラーは、熱及び冷中性子ビームを偏極するための光学素子であり、実機への応用には高偏極率であるとともに必要な外部磁場を小さく抑えること、即ち偏極スーパーミラーを構成する磁気多層膜が磁気的にソフトであることが重要である。本発表では、J-PARC MLFの共用ビームラインBL17等を用いて得られた偏極スーパーミラーの高偏極率化、及び磁気多層膜の軟磁性化を目指しこれを構成する多層膜特有の磁気特性の解明に関する成果について議論する。
