다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

We introduce the 2D counterpart of layered black phosphorus, which we call phosphorene, as an unexplored p-type semiconducting material. Same as graphene and MoS2, single-layer phosphorene is flexible and can be mechanically exfoliated. We find phosphorene to be stable and, unlike graphene, to have an inherent, direct, and appreciable band gap. Our ab initio calculations indicate that the band gap is direct, depends on the number of layers and the in-layer strain, and is significantly larger than the bulk value of 0.31–0.36 eV. The observed photoluminescence peak of single-layer phosphorene in the visible optical range confirms that the band gap is larger than that of the bulk system. Our transport studies indicate a hole mobility that reflects the structural anisotropy of phosphorene and complements n-type MoS2. At room temperature, our few-layer phosphorene field-effect transistors with 1.0 μm channel length display a high on-current of 194 mA/mm, a high hole field-effect mobility of 286 cm2/V·s, and an...

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Phosphorene: An Unexplored 2D Semiconductor with a High Hole Mobility

There is still an ongoing effort to search for sustainable, clean and highly efficient energy generation to satisfy the energy needs of modern society. Among various advanced technologies, electrocatalysis for the oxygen evolution reaction (OER) plays a key role and numerous new electrocatalysts have been developed to improve the efficiency of gas evolution. Along the way, enormous effort has been devoted to finding high-performance electrocatalysts, which has also stimulated the invention of new techniques to investigate the properties of materials or the fundamental mechanism of the OER. This accumulated knowledge not only establishes the foundation of the mechanism of the OER, but also points out the important criteria for a good electrocatalyst based on a variety of studies. Even though it may be difficult to include all cases, the aim of this review is to inspect the current progress and offer a comprehensive insight toward the OER. This review begins with examining the theoretical principles of electrode kinetics and some measurement criteria for achieving a fair evaluation among the catalysts. The second part of this review acquaints some materials for performing OER activity, in which the metal oxide materials build the basis of OER mechanism while non-oxide materials exhibit greatly promising performance toward overall water-splitting. Attention of this review is also paid to in situ approaches to electrocatalytic behavior during OER, and this information is crucial and can provide efficient strategies to design perfect electrocatalysts for OER. Finally, the OER mechanism from the perspective of both recent experimental and theoretical investigations is discussed, as well as probable strategies for improving OER performance with regards to future developments.

Electrocatalysis for the oxygen evolution reaction: recent development and future perspectives

Preceding the current interest in layered materials for electronic applications, research in the 1960's found that black phosphorus combines high carrier mobility with a fundamental band gap. We introduce its counterpart, dubbed few-layer phosphorene, as a new 2D p-type material. Same as graphene and MoS2, phosphorene is flexible and can be mechanically exfoliated. We find phosphorene to be stable and, unlike graphene, to have an inherent, direct and appreciable band-gap that depends on the number of layers. Our transport studies indicate a carrier mobility that reflects its structural anisotropy and is superior to MoS2. At room temperature, our phosphorene field-effect transistors with 1.0 um channel length display a high on-current of 194 mA/mm, a high hole field-effect mobility of 286 cm2/Vs, and an on/off ratio up to 1E4. We demonstrate the possibility of phosphorene integration by constructing the first 2D CMOS inverter of phosphorene PMOS and MoS2 NMOS transistors.

Phosphorene: A New 2D Material with High Carrier Mobility

Magnetism and ferroelectricity are essential to many forms of current technology, and the quest for multiferroic materials, where these two phenomena are intimately coupled, is of great technological and fundamental importance. Ferroelectricity and magnetism tend to be mutually exclusive and interact weakly with each other when they coexist. The exciting new development is the discovery that even a weak magnetoelectric interaction can lead to spectacular cross-coupling effects when it induces electric polarization in a magnetically ordered state. Such magnetic ferroelectricity, showing an unprecedented sensitivity to ap plied magnetic fields, occurs in 'frustrated magnets' with competing interactions between spins and complex magnetic orders. We summarize key experimental findings and the current theoretical understanding of these phenomena, which have great potential for tuneable multifunctional devices.

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Multiferroics: a magnetic twist for ferroelectricity

β-Li3PS4 is a solid electrolyte with high Li+ conductivity, applicable to sulfide-based all-solid-state batteries. While a β-Li3PS4-synthesized by solid-state reaction forms only in a narrow 300-450 °C temperature range upon heating, β-Li3PS4 is readily available by liquid-phase synthesis through low-temperature thermal decomposition of complexes composed of PS43- and various organic solvents. However, the conversion mechanism of β-Li3PS4 from these complexes is not yet understood. Herein, we proposed the synthesis mechanism of β-Li3PS4 from Li3PS4·acetonitrile (Li3PS4·ACN) and Li3PS4·1,2-dimethoxyethane (Li3PS4·DME), whose structural similarity with β-Li3PS4 would reduce the nucleation barrier for the formation of β-Li3PS4. Synchrotron X-ray diffraction clarified that both complexes possess similar layered structures consisting of alternating Li2PS4- and Li+-ACN/DME layers. ACN/DME was removed from these complexes upon heating, and rotation of the PS4 tetrahedra induced a uniaxial compression to form the β-Li3PS4 framework.

Formation Mechanism of β-Li3PS4 through Decomposition of Complexes.

We report formation of magnetic textures in the ferromagnetic (FM) phase of $\mathrm{L}{\mathrm{a}}_{1\ensuremath{-}x}\mathrm{S}{\mathrm{r}}_{x}\mathrm{Mn}{\mathrm{O}}_{3}$ for $x=0.125$; these textures are magnetic bubbles, magnetic stripe domains, and forced FM states. In situ Lorentz microscopy (LM) observations show that magnetic bubbles exist in the FM insulating phase accompanying the formation of the charge/orbital ordering (CO/OO). Furthermore, stable magnetic bubbles still exist in an intermediate temperature region between the CO/OO (${T}_{\mathrm{CO}}=155\phantom{\rule{0.16em}{0ex}}\mathrm{K}$) and FM (${T}_{\mathrm{C}}=190\phantom{\rule{0.16em}{0ex}}\mathrm{K}$) transition temperatures. These magnetic bubbles are believed to originate from the magnetocrystalline anisotropy and the dipole-dipole interaction in the FM phase. Based on in situ LM observations as a function of both temperature and the strength of the external magnetic field applied, a magnetic field--temperature phase diagram is constructed, exhibiting the stabilizing regions of the magnetic bubbles in the FM phase of $\mathrm{L}{\mathrm{a}}_{0.875}\mathrm{S}{\mathrm{r}}_{0.125}\mathrm{Mn}{\mathrm{O}}_{3}$.

Field-temperature phase diagram of magnetic bubbles spanning charge/orbital ordered and metallic phases in L a 1 − x S r x Mn O 3 ( x = 0.125 )

A characteristic nonlinear electric responses were found in a charge ordered type ferroelectrics LuFe2O4 with less oxygen deficiency. Cole – Cole circular in the dielectric response varies in the function of the amplitude of the AC electric field. With a synchrotron radiation diffraction experiment under the current revealed the variation of the coherence length of the polar charge ordered W-layer along c-axis. The nonlinear response with the increase of the electronic current may relates to the electron hopping in the charge stripe structure.

Electric Field Response of Stoichiometric LuFe2O4

We examined microstructures related to the charge ordering in YFe2O4-delta, by transmission electron microscopy. It is found that two types of characteristic diffuse scatterings appear at room temperature. One is characteristic diffuse streaks elongated along the [0001] direction through the (1/3 1/3 2/3 0)-type reciprocal positions and the other is diffuse spots at (1/3 - eta 1/3 - eta 2/3 + 2eta 0)-type incommensurate positions (eta approximately 0.066). Real-space images revealed that the former diffuse scattering is related to nano-domains due to the charge ordering and the latter one is related to those due to vacancy ordering. The presence of the nano-sized domains should be strongly related to the dielectric anomalies found in YFe2O4-delta.

Nano-sized domains related to dielectric anomaly in YFe2O4-δ

Preparation of LiNi1/3Mn1/3Co1/3O2/Li3PS4 cathode composite particles using a new liquid-phase process and application to all-solid-state lithium batteries

Shigeo Mori

Papers

Formation Mechanism of β-Li3PS4 through Decomposition of Complexes.

Field-temperature phase diagram of magnetic bubbles spanning charge/orbital ordered and metallic phases in L a 1 − x S r x Mn O 3 ( x = 0.125 )

Electric Field Response of Stoichiometric LuFe2O4

Nano-sized domains related to dielectric anomaly in YFe2O4-δ

Preparation of LiNi1/3Mn1/3Co1/3O2/Li3PS4 cathode composite particles using a new liquid-phase process and application to all-solid-state lithium batteries