687 citations · 9.2k across the 149 of their papers we have counts for
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High-entropy van der Waals materials formed from mixed metal dichalcogenides, halides and phosphorus trisulfides
Tianping Ying, Tongxu Yu, Yu-Shien Shiah +4
The charge, spin, and composition degrees of freedom in high-entropy alloy endow it with tunable valence and spin states, infinite combinations and excellent mechanical performance…
Crystal structure built from a GeO-GeO polyhedra network with high thermal stability: -SrGeO
Christian A. Niedermeier, Jun-ichi Yamaura, Jiazhen Wu +4
By tackling the challenge of extending transparent oxide semiconductors to Ge based oxides, we have found a not-yet-reported crystal structure, named -SrGeO, which is co…
Shallow Valence Band of Rutile GeO and P-type Doping
Christian A. Niedermeier, Keisuke Ide, Takayoshi Katase +2
GeO has an -quartz-type crystal structure with a very wide fundamental band gap of 6.6 eV and is a good insulator. Here we find that the stable rutile-GeO polymorph with…
Higher-Order Topological Crystalline Insulating Phase and Quantized Hinge Charge in Topological Electride Apatite
Motoaki Hirayama, Ryo Takahashi, Satoru Matsuishi +2
In higher-order topological insulators, bulk and surface electronic states are gapped, while there appear gapless hinge states protected by spatial symmetry. Here we show by ab ini…
Natural van der Waals heterostructural single crystals with both magnetic and topological properties
Jiazhen Wu, Fucai Liu, Masato Sasase +8
Heterostructures having both magnetism and topology are promising materials for the realization of exotic topological quantum states while challenging in synthesis and engineering.…
Heteroepitaxial Thin-Film Growth of a Ternary Nitride Semiconductor CaZn2N2
Masatake Tsuji, Kota Hanzawa, Hiroyuki Kinjo +2
Zinc-based nitride CaZn2N2 films grown by molecular beam epitaxy (MBE) with a plasma-assisted active nitrogen-radical source are promising candidates of next-generation semiconduct…
Stabilization and heteroepitaxial growth of metastable tetragonal FeS thin films by pulsed laser deposition
Kota Hanzawa, Masato Sasase, Hidenori Hiramatsu +1
Pulsed laser deposition, a non-equilibrium thin-film growth technique, was used to stabilize metastable tetragonal iron sulfide (FeS), the bulk state of which is known as a superco…
Tunable light-emission through the range 1.8-3.2 eV and p-type conductivity at room temperature for nitride semiconductors, Ca(Mg1-xZnx)2N2 (x=0-1)
Masatake Tsuji, Hidenori Hiramatsu, Hideo Hosono
The ternary nitride CaZn2N2, composed only of earth-abundant elements, is a novel semiconductor with a band gap of 1.8 eV. First-principles calculations predict that continuous Mg…
Efficient Construction Method for Phase Diagrams Using Uncertainty Sampling
Kei Terayama, Ryo Tamura, Yoshitaro Nose +4
We develop a method to efficiently construct phase diagrams using machine learning. Uncertainty sampling (US) in active learning is utilized to intensively sample around phase boun…
Ternary Inorganic Electrides with mixed bonding
Junjie Wang, Qiang Zhu, Zhenhai Wang +1
A high-throughput screening based on first-principles calculations was performed to search for new ternary inorganic electrides. From the available materials database, we identifie…
Electronic correlation in the quasi-two-dimensional electride YC
M. Hiraishi, K. M. Kojima, I. Yamauchi +10
Magnetic properties of the electride compound YC were investigated by muon spin rotation and magnetic susceptibility on two samples with different form (poly- and single-crysta…
Electrides as a New Platform of Topological Materials
Motoaki Hirayama, Satoru Matsuishi, Hideo Hosono +1
Recent discoveries of topological phases realized in electronic states in solids have revealed an important role of topology, which ubiquitously appears in various materials in nat…
Highly hydrogen-sensitive thermal desorption spectroscopy system for quantitative analysis of low hydrogen concentration (~1 x 10^16 atoms/cm3) in thin-film samples
Taku Hanna, Hidenori Hiramatsu, Isao Sakaguchi +1
We developed a highly hydrogen-sensitive thermal desorption spectroscopy (HHS-TDS) system to detect and quantitatively analyze low hydrogen concentrations in thin films. The system…
Exploiting ITO colloidal nanocrystals for ultrafast pulse generation
Qiangbing Guo, Yudong Cui, Yunhua Yao +7
Dynamical materials that capable of responding to optical stimuli have always been pursued for designing novel photonic devices and functionalities, of which the response speed and…
Phonon scattering limited mobility in the representative cubic perovskite semiconductors SrGeO, BaSnO and SrTiO
Christian A. Niedermeier, Yu Kumagai, Keisuke Ide +4
Cubic perovskite oxides are emerging high-mobility transparent conducting oxides (TCOs), but Ge-based TCOs had not been known until the discovery of metastable cubic SrGeO. $0.…
Electron effective mass and mobility limits in degenerate perovskite stannate BaSnO
Christian A. Niedermeier, Sneha Rhode, Keisuke Ide +4
The high room temperature mobility and the electron effective mass in BaSnO are investigated in depth by evaluation of the free carrier absorption observed in infrared spectra…
Semimetallic "Electride Bands" Derived from Interlayer Electrons in Quasi-Two-Dimensional Electride YC
Koji Horiba, Ryu Yukawa, Taichi Mitsuhashi +10
Two-dimensional (2D) electrides are a new concept material in which anionic electrons are confined in the interlayer space between positively charged layers. We have performed angl…
Novel solid-phase epitaxy for multi-component materials with extremely high vapor pressure elements: An application to KFe2As2
Taisuke Hatakeyama, Hikaru Sato, Hidenori Hiramatsu +2
We propose a novel solid-phase epitaxy technique applicable to high annealing temperatures up to 1000 C without re-vaporization of alkali metal elements with high vapor pressures.…
Cage Electron-Hydroxyl Complex State as Electron Donor in Mayenite
M. Hiraishi, K. M. Kojima, M. Miyazaki +6
It is inferred from the chemical shift of muon spin rotation (SR) spectra that muons implanted in pristine (fully oxidized) mayenite, [CaAlO[$\square_…
Ferromagnetic instability of interlayer floating electrons in quasi-two-dimensional electride YC
Takeshi Inoshita, Noriaki Hamada, Hideo Hosono
Ab initio electronic structure calculations show that the recently identified quasi-two-dimensional electride YC is a weak itinerant ferromagnet or at least close to a ferromag…
n-type conversion of SnS by isovalent ion substitution: Geometrical doping as a new doping route
Fan-Yong Ran, Zewen Xiao, Yoshitake Toda +3
Tin monosulfide (SnS) is a naturally p-type semiconductor with a layered crystal structure, but no reliable n-type SnS has been obtained by conventional aliovalent ion substitution…
Hydrogen Ordering and New Polymorph of Layered Perovskite Oxyhydrides: Sr2VO4-xHx
Joonho Bang, Satoru Matsuishi, Haruhiro Hiraka +7
Compositionally tunable vanadium oxyhydrides Sr2VO4-xHx (x = 0 - 1) without considerable anion vacancy were synthesized by high-pressure solid state reaction. The crystal structure…
Layered Compounds BaM2Ge4Ch6 (M = Rh, Ir and Ch = S, Se) with Pyrite-Type Building Blocks and Ge-Ch Heteromolecule-Like Anions
Hechang Lei, Jun-ichi Yamaura, Jiangang Guo +3
Structure and chemical features of layered compounds BaM2Ge4Ch6 (M = Rh, Ir; Ch = S, Se) synthesized under high-pressure and high-temperature method are systematically studied. The…
Electric double-layer transistor using layered iron selenide Mott insulator TlFe1.6Se2
Takayoshi Katase, Hidenori Hiramatsu, Toshio Kamiya +1
A1-xFe2-ySe2 (A = K, Cs, Rb, Tl) are recently discovered iron-based superconductors with critical temperatures (Tc) ranging up to 32 K. Their parent phases have unique properties w…