研究者詳細 - 田中　将嗣

論文 - 田中　将嗣

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Bulk Synthesis and Superconductivity of Rock Salt-Type, Nitrogen-Rich, Zirconium-Deficient Nitrides, Zr1–xN 査読有り国際誌

Masashi Tanaka, Masaya Fujioka, Duncan H. Gregory, Kei Inumaru

Chemistry of Materials ( American Chemical Society ) 37 ( 10 ) 3747 - 3756 2025年05月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Zirconium nitrides were derived from crystalline powders of layer-structured ZrNCl via ammonothermal dechlorination at various temperatures under flowing ammonia gas. Regardless of which polymorph of ZrNCl was employed as a starting material, the products of the ammonothermal dechlorination reactions were zirconium nitride powders with the rock salt structure. The size of the cubic lattice parameter was found to be dependent on the ammonia flow rate. Each of the synthesized zirconium nitrides is nonstoichiometric and nitrogen-rich (zirconium-deficient), Zr<inf>1−x</inf>N, and some exhibit superconductivity at subambient temperature. The superconducting transition temperature (T<inf>c</inf>) of each of the nitrides scales linearly with the corresponding cubic unit cell volume (lattice parameter, a) and the N/Zr ratio. This paper represents the first report of a superconducting dome in bulk nitrogen-rich zirconium nitrides with a rock-salt-type structure; to date, a unique characteristic among superconducting rock salt phases.

DOI： 10.1021/acs.chemmater.5c00175

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Hydrogen-Assisted Mg Intercalation into 2H-TaS2 査読有り国際誌

Masaya Fujioka, Khurelbaatar Zagarzusem, Suguru Iwasaki, Aman Sharma, Konosuke Watanabe, Rei Nakayama, Mizuki Momai, Yuki Yamaguchi, Hiroyuki Shimada, Katsuhiro Nomura, Yasunobu Mizutani, Hirofumi Sumi, Masashi Tanaka, Melbert Jeem, Mineyuki Hattori, Hiroyuki Saitoh, Toshinori Ozaki, Masanori Nagao, Kazuki Nagashima

Journal of the American Chemical Society 146 ( 50 ) 34324 - 34332 2024年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Intercalation reactions are highly dependent on the electronic and structural relationships between host and guest materials. It is difficult for divalent ions, such as Mg, to undergo intercalation reactions compared with monovalent cations. However, further development of synthetic techniques for controlling divalent ions is strongly demanded to advance applied chemistry and fundamental physics. In this study, the cointercalation of Mg and H into the transition-metal chalcogenide TaS<inf>2</inf> was utilized to obtain bulk polycrystalline Mg<inf>x</inf>H<inf>y</inf>TaS<inf>2</inf>. Introduced H can be extracted via postannealing at approximately 400 °C without altering the crystal structure. This study clarified the relationship between superconducting properties and electronic carrier density from the perspectives of calculations and experiments, along with the advantages of using hydride as a multivalent intercalation reaction.

DOI： 10.1021/jacs.4c07294

DOI： 10.1021/jacs.4c07294

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Intercalation on Transition Metal Trichalcogenides via a Quasi-Amorphous Phase with 1D Order 査読有り

Masaya Fujioka, Melbert Jeem, Kento Sato, Masashi Tanaka, Kazuki Morita, Taizo Shibuya, Kiyonori Takahashi, Suguru Iwasaki, Akira Miura, Masanori Nagao, Satoshi Demura, Hideaki Sakata, Madoka Ono, Hideo Kaiju, Junji Nishii

Advanced Functional Materials ( Wiley ) 33 ( 10 ) 2208702 2023年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Intercalation into 1D transition metal trichalcogenides (TMTs) in which fibers are bonded by a weak van der Waals force can be expected to create various intercalation compounds and develop unique physical properties according to the combination of the host materials and guest ions. However, structural changes via intercalation into 1D TMTs are not as simple as those in 2D transition metal dichalcogenides (TMDs) and are still not understood comprehensively. ZrTe3: a typical compound with a 1D trigonal prismatic structure, belongs to TMTs. Herein, through the Ag introduction to ZrTe3 via solid-state intercalation, a novel crystal phase with a 1D octahedral structure and a quasi-amorphous (QA) phase during the structural transition are discovered; the QA phase is a novel state of matter in which long-range order is lost while retaining 1D order. Based on the Ag concentration, the transport properties are flexibly modulated from superconductivity to semiconductivity. Density functional theory calculations indicate the attraction between Ag ions and the pair diffusion due to their attraction. Furthermore, judging the attraction or repulsion between guest ions predicts whether to induce a QA phase or simple lattice expansion like the intercalation into 2D TMDs.

DOI： 10.1002/adfm.202208702

DOI： 10.1002/adfm.202208702

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Modification of the synthesis of layered titanium chloride nitride 査読有り

Masashi Tanaka,Noriyuki Kataoka,Haruya Kobayashi,Masaya Fujioka,Masaru Oda,Aishi Yamamoto,Kensei Terashima,Junji Nishii,Hiromi Tanaka,Takayoshi Yokoya

Materials Research Bulletin ( Elsevier ) 153 111896 2022年05月

Superconductivity in the α-Form Layer Structured Metal Nitride Halide 招待有り査読有り国際誌

M. Tanaka, N. Kataoka, T. Yokoya

Condensed Matter ( MDPI ) 7 ( 2 ) 33 2022年04月

Synthetic Route of Layered Titanium Nitride Chloride TiNCl Using Sodium Amide 査読有り国際誌

Tanaka M., Kataoka N., Matsumoto R., Inumaru K., Takano Y., Yokoya T.

ACS Omega ( American Chemical Society ) 7 ( 7 ) 6375 - 6380 2022年02月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

A synthetic route in a closed system for layered titanium nitride chloride TiNCl has been developed using sodium amide NaNH2 as a nitrogen source. A highly crystalline sample is obtained by an appropriate thermal decomposition of aminated titanium chloride. The obtained TiNCl was also characterized using electronic resistivity measurement and photoemission spectroscopy. TiNCl showed hopping conduction compatible with an in-gap state revealed by photoelectron spectroscopy. However, it appeared highly electron-doped, albeit without showing superconductivity. Comparison with the spectrum of superconducting sodium-doped samples suggests the presence of the microstructure required to exhibit superconductivity.

DOI： 10.1021/acsomega.1c06986

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Soft x-ray irradiation induced metallization of layered TiNCl 査読有り国際誌

Noriyuki Kataoka, Masashi Tanaka, Wataru Hosoda, Takumi Taniguchi, Shin-ichi Fujimori, Takanori Wakita, Yuji Muraoka, Takayoshi. Yokoya

Journal of Physics Condensed Matter 33 ( 3 ) 035501 2020年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

We have performed soft x-ray spectroscopy in order to study the photoirradiation time dependence of the valence band structure and chemical states of layered transition metal nitride chloride TiNCl. Under the soft x-ray irradiation, the intensities of the states near the Fermi level (E F) and the Ti3+ component increased, while the Cl 2p intensity decreased. Ti 2p-3d resonance photoemission spectroscopy confirmed a distinctive Fermi edge with Ti 3d character. These results indicate the photo-induced metallization originates from deintercalation due to Cl desorption, and thus provide a new carrier doping method that controls the conducting properties of TiNCl.

DOI： 10.1088/1361-648X/abbbc3

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Intermittent dynamics of antiferromagnetic phase in inhomogeneous iron-based chalcogenide superconductor 査読有り

Ricci A., Campi G., Joseph B., Poccia N., Innocenti D., Gutt C., Tanaka M., Takeya H., Takano Y., Mizokawa T., Sprung M., Saini N.L.

Physical Review B 101 ( 2 ) 2020年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 American Physical Society. The coexistence of phases, characterized by different electronic degrees of freedom, commonly occurs in layered superconductors. Among them, alkaline intercalated chalcogenides are model systems showing the microscale coexistence of paramagnetic (PAR) and antiferromagnetic (AFM) phases, however, the temporal behavior of different phases is still unknown. Here, we report a visualization of the atomic motion in the granular phase of KxFe2-ySe2 using x-ray photon correlation spectroscopy. Unlike the PAR phase, the AFM texture reveals an intermittent dynamics with avalanches as in martensites. When cooled down across the superconducting transition temperature Tc, the AFM phase goes through an anomalous slowing behavior, suggesting a direct relationship between the atomic motions in the AFM phase and the superconductivity. In addition to providing compelling evidence of avalanchelike dynamics in a layered superconductor, the results provide a basis for different theoretical models to describe the quantum states in inhomogeneous solids.

DOI： 10.1103/PhysRevB.101.020508

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Change in the electronic structure of the bismuth chalcogenide superconductor CsBi4-xPbxTe6 by dissociation of the bismuth dimers 査読有り国際誌

Hiroyuki Okazaki,Kensei Terashima, David Billington, Keiji Iwata, Takanori Wakita, Masashi Tanaka, Yoshihiko Takano, Yuji Muraoka, Takayoshi Yokoya

Journal of Physics: Condensed Matter 32 ( 14 ) 145501 2020年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

CsBi4-xPbxTe6 is synthesized and the superconductivity associated with the structural transition from Pb substitution is studied. Photoemission spectroscopy measurements are performed in order to elucidate the relationship between the electronic structure and the occurrence of the superconductivity. When Bi is substituted with Pb, an electron doping-like change in the electronic structure is directly observed which is contrary to the naive expectation of hole doping. This observation is consistent with band structure calculations and appears to be a unique characteristic of CsBi4-xPbxTe6 because of the dissociation of Bi dimers upon Pb substitution. These results indicate that it may be possible to control the electron and hole doping via manipulating the Bi dimers through Pb substitution.

DOI： 10.1088/1361-648X/ab5e1a

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Self-assembled lamellar-type nanostructure in manganite spinel (Co,Mn,Fe)3O4 査読有り国際誌

Y. Horibe, M. Ishimatsu, S. Takeyama, S. Mori, M. Kudo, M. Auchi, M. Tanaka, Y. Murakami

Applied Physics Letters 115 ( 23 ) 232401 2019年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Distinct nanostructures in (Co,Mn,Fe)3O4 were investigated using X-ray diffraction techniques combined with transmission and scanning transmission electron microscopy, as well as energy dispersive X-ray spectroscopy. The size of the checkerboard nanostructure increased with annealing, followed by the appearance of lamellar nanostructures comprising different types of platelike nanodomains because of nanoscopic spinodal decomposition of Mn and Fe ions. Remarkable local strain relaxation at the nanoscale associated with the domain size is suggested to play an important role in the stabilization of these checkerboard and lamellar nanostructures.

DOI： 10.1063/1.5123780

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µ-PES Studies on TiNCl and Quasi-two-dimensional Superconductor Na-intercalated TiNCl 査読有り国際誌

Kataoka Noriyuki, Terashima Kensei, Tanaka Masashi, Hosoda Wataru, Taniguchi Takumi, Wakita Takanori, Muraoka Yuji, Yokoya Takayoshi

Journal of the Physical Society of Japan ( Physical Society of Japan ) 88 ( 10 ) 104709 - 1-5 2019年09月

記述言語：英語掲載種別：研究論文（学術雑誌）

Electron-doped TiNCl is a superconductor, for which exotic mechanisms of the superconductivity have been discussed. However, difficulty in preparing large single-phase samples has prevented the direct observation of its electronic structure and how that changes with electron doping. In this study, micro-photoemission spectroscopy (µ-PES) was used to reveal the electronic structures of TiNCl and Na-intercalated TiNCl (Na-TiNCl). Comparison of Ti 2p core-level spectra shows the enhancement of a spectral feature in Na-TiNCl that suggests an increase in its metallic character. This indicates the introduction of electron carriers to the TiNCl layers. Although the overall valence band electronic structure of parent TiNCl could be reproduced by first-principle calculations, that of Na-TiNCl showed a marked deviation from the rigid band model near the Fermi level (EF). The spectral shape observed near EF of Na-TiNCl was found to be similar to a result in early transition metal oxides that has been attributed to the effect of strong electron correlation. The present study also demonstrated the usefulness of µ-PES to obtain reliable electronic structure data for samples that are difficult to make at large sizes.

DOI： 10.7566/JPSJ.88.104709

その他リンク： https://ci.nii.ac.jp/naid/40022034179

Growth and physical properties of Ce(O,F)Sb(S,Se)2 single crystals with site-selected chalcogen atoms 査読有り

M. Nagaoa, M. Tanaka, A. Miura, M. Kitamura, K. Horiba, S. Watauchi, Y. Takano, H. Kumigashira, I. Tanaka

Solid State Communications 289 38 - 42 2018年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Ce(O,F)Sb(S,Se)2 single crystals were successfully grown using a CsCl/KCl flux method. The obtained crystals have a plate-like shape with the typical size of 1–2 mm and well-developed ab-plane, which enables X-ray single crystal structural analysis. The Ce(O,F)Sb(S,Se)2 crystallizes in a monoclinic space group, P21/m, with lattice parameters of a = 4.121(7) Å, b = 4.109(7) Å, c = 13.233(15) Å, β = 97.94(7) °. It is composed of alternate stacking of Ce-(O,F) and Sb-SSe layers, and the Sb-SSe layer includes selective occupation of Se atoms in its in-plane site. The valence state of Ce is estimated to be Ce3+ by X-ray absorption fine spectroscopy analysis. The single crystals show an insulating behavior, and a magnetic ordering around 6 K.

DOI： 10.1016/j.ssc.2018.12.004

その他リンク： https://www.sciencedirect.com/science/article/pii/S0038109818303466?dgcid=author

Vapor-Phase Growth and Structural Characterization of Single Crystals of Magnesium Doped Two-Dimensional Fullerene Polymer Mg2C60 査読有り

Masashi Tanaka, Shoji Yamanaka

Crystal Growth & Design 18 ( 7 ) 3877 - 3882 2018年07月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Single crystals of magnesium doped fullerene polymer Mg2C60 can be directly grown via a binary vapor-phase mixture of Mg and C60, in sealed glass tubes at elevated temperatures. This is the first single crystal, in metal-doped two-dimensional fullerene polymers, which enables precise X-ray structural refinement. The Mg2C60 crystallizes in a monoclinic space group, I2/m, with lattice parameters of a = 9.324(2) Å, b = 9.041(2) Å, c = 14.817(3) Å, and β = 91.699(10)°. A Mg atom is located at each tetrahedral fullerene ball interstice, where the shortest Mg-C distance is 2.341(2) Å, suggesting that the Mg cation is in van der Waals contact with carbon p orbitals. The precise structure of the two-dimensional fullerene polymer network is characterized by comparison with structural data reported previously on powder samples.

DOI： 10.1021/acs.cgd.8b00186

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Influence of Oxidation in Starting Material Sn on Electric Transport Properties of SnSe Single Crystals 査読有り

Aichi Yamashita, Osamu Ogiso, Ryo Matsumoto, Masashi Tanaka, Hiroshi Hara, Hiromi Tanaka, Hiroyuki Takeya, Chul-Ho Lee, Yoshihiko Takano

J. Phys. Soc. Jpn. 87 ( 6 ) 065001-1 - 065001-2 2018年06月

記述言語：英語掲載種別：研究論文（学術雑誌）

We found that the electronic transport property of SnSe single crystals was sensitively affected by oxidation in raw Sn. Semiconducting SnSe single crystals were obtained by using Sn of grain form as a starting material while powder Sn resulted in metallic SnSe. X-ray photoelectron spectroscopy analysis revealed that the surfaces of raw Sn were oxidized, which volume fraction is lower in grain Sn. This indicates that the amount of oxygen in raw Sn is the key factor for the electronic transport property of SnSe.

DOI： 10.7566/JPSJ.87.065001

その他リンク： https://journals.jps.jp/doi/10.7566/JPSJ.87.065001

Quantum conductance-temperature phase diagram of granular superconductor KxFe2-ySe2 査読有り

C. C. Soares, M. ElMassalami, Y.Yanagisawa, M. Tanaka, H. Takeya, Y. Takano

Scientific Reports 8 ( 1 ) 7041 2018年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

It is now well established that the microstructure of Fe-based chalcogenide K x Fe2-y Se2 consists of, at least, a minor (~15 percent), nano-sized, superconducting K s Fe2Se2 phase and a major (~85 percent) insulating antiferromagnetic K2Fe4Se5 matrix. Other intercalated A 1-x Fe2-y Se2 (A = Li, Na, Ba, Sr, Ca, Yb, Eu, ammonia, amide, pyridine, ethylenediamine etc.) manifest a similar microstructure. On subjecting each of these systems to a varying control parameter (e.g. heat treatment, concentration x,y, or pressure p), one obtains an exotic normal-state and superconducting phase diagram. With the objective of rationalizing the properties of such a diagram, we envisage a system consisting of nanosized superconducting granules which are embedded within an insulating continuum. Then, based on the standard granular superconductor model, an induced variation in size, distribution, separation and Fe-content of the superconducting granules can be expressed in terms of model parameters (e.g. tunneling conductance, g, Coulomb charging energy, E c, superconducting gap of single granule, Δ, and Josephson energy J = πΔg/2). We show, with illustration from experiments, that this granular scenario explains satisfactorily the evolution of normal-state and superconducting properties (best visualized on a $${\boldsymbol{g}}{\boldsymbol{-}}\frac{{{\boldsymbol{E}}}-{{\boldsymbol{c}}}}{{\boldsymbol{\Delta }}}{\boldsymbol{-}}{\boldsymbol{T}}$$ g - E c Δ - T phase diagram) of A x Fe2-y Se2 when any of x, y, p, or heat treatment is varied.

DOI： 10.1038/s41598-018-25052-0

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Observation of zero resistance in as-electrodeposited FeSe 査読有り

Aichi Yamashita, Ryo Matsumoto, Masashi Tanaka, Hiroshi Hara, Kazumasa Iida, Bernhard Holzapfel, Hiroyuki Takeya, Yoshihiko Takano

Solid State Communications 270 72 - 75 2018年02月

記述言語：英語掲載種別：研究論文（学術雑誌）

Superconducting FeSe films were electrochemically deposited on rolling-assisted biaxially textured substrate (RABiTS) tape. We observed zero resistivity in the as-electrodeposited FeSe film prepared on the RABiTS when the appropriate voltage was applied while it was dipped into the solution. When the RABiTS tape was dipped in the solution without applying voltage, a thin Se film was deposited on the substrate. The compositional ratio of the FeSe film got closer to the stoichiometric ratio with decreasing the dipping time before applying voltage.

DOI： 10.1016/j.ssc.2017.11.018

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Low-Temperature Carrier Transport in Ionic-Liquid-Gated Hydrogen-Terminated Silicon 査読有り

Yosuke Sasama, Takahide Yamaguchi, Masashi Tanaka, Hiroyuki Takeya, Yoshihiko Takano

Journal of the Physical Society of Japan 86 ( 11 ) 114703-1 - 114703-5 2017年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

We fabricated ionic-liquid-gated field-effect transistors on the hydrogen-terminated (111)-oriented surface of undoped silicon. Ion implantation underneath electrodes leads to good ohmic contacts, which persist at low temperatures down to 1.4 K. The sheet resistance of the channel decreases by more than five orders of magnitude as the gate voltage is changed from 0 to -1.6V at 220 K. This is caused by the accumulation of hole carriers. The sheet resistance shows thermally activated behavior at temperatures below 10 K, which is attributed to hopping transport of the carriers. The activation energy decreases towards zero with increasing carrier density, suggesting the approach to an insulator-metal transition. We also report the variation of device characteristics induced by repeated sweeps of the gate voltage.

DOI： 10.7566/JPSJ.86.114703

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Superconductivity and its enhancement under high pressure in "F-free" single crystals of CeOBiS2 査読有り

Masashi Tanaka, Masanori Nagao, Ryo Matsumoto, Noriyuki Kataoka, Ikuo Ueta, Hiromi Tanaka, Satoshi Watauchi, Isao Tanaka, Yoshihiko Takano

Journal of Alloys and Compounds 722 ( 25 ) 467 - 473 2017年10月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

“F-free” CeOBiS2 single crystals have successfully grown, thoroughly eliminating a concern about F-contamination by using a high-purity CsCl flux. The obtained crystals have a plate-like shape with a size of 1.0–3.0 mm in the well-developed plane. Single crystal X-ray structural analysis clearly revealed that the CeOBiS2 crystallizes with a space group P4/nmm (with lattice parameters of a = 4.0189 (6) Å, c = 13.573 (2) Å). The bond valence sum estimation and X-ray photoelectron spectroscopy analysis showed that the chemical state of Ce was in the mixed valence of Ce3+ and Ce4+. The single crystals show superconductivity with zero resistivity at ∼1.3 K. This is the first conclusive evidence of superconductivity driven by Ce valence fluctuation in surely non-doped CeOBiS2. The superconducting transition temperature was enhanced up to ∼3.8 K by applying hydrostatic pressure.

DOI： 10.1016/j.jallcom.2017.06.125

その他リンク： http://www.sciencedirect.com/science/article/pii/S0925838817321254

Quenching Dependence on Superconductivity in the Synthesizing Process of Single Crystals of RbxFe2-ySe2 査読有り

Masashi Tanaka, Hiroyuki Takeya, Yoshihiko Takano

Solid State Communications 26 32 - 36 2017年10月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Superconducting single crystals of Rb-intercalated FeSe compounds RbxFe2-ySe2 were prepared by using a starting material of Rb2Se as a Rb source. The superconducting properties and the surface microstructures were systematically controlled by varying the cooling rate in the quenching process. The higher cooling rate in the sample provided a higher superconducting transition temperature with highly connected superconducting mesh-like surface structure. Extremely slow-cooling process led to the complete isolation between the superconducting domains.

DOI： 10.1016/j.ssc.2017.08.002

その他リンク： http://www.sciencedirect.com/science/article/pii/S0038109817302405

Superconducting joints using Bi-added PbSn solders 査読有り

Ryo Matsumoto, Hirotsugu Iwata, Aichi Yamashita, Hiroshi Hara, Gen Nishijima, Masashi Tanaka, Hiroyuki Takeya, Yoshihiko Takano

Applied Physics Express 10 ( 9 ) 093102 2017年08月

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