Hiroshi Ito

Following the previous achievement of highly crystalline α-Ga 2 O 3 thin films on c -plane sapphire, the growth of corundum-structured α-(Al x Ga 1- x ) 2 O 3 was examined aiming at the future application of α-(Al x Ga 1- x ) 2 O 3 /Ga 2 O 3 heterostructures to power devices and other functional devices. The results show the control of x and band gap up to 0.81 and 7.8 eV, respectively, maintaining the dominant corundum structure. The transmission electron microscope observation suggested the fo

The pressure phase diagram of κ-(BEDT-TTF) 2 Cu[N(CN) 2 ]Cl is determined by measuring the intralayer and interlayer resistivities. With increase of pressure, nonmetallic behavior of resistivity is suppressed and a metallic phase is stabilized, yielding the phase reentrance near critical pressure region. Concurrently, an incomplete superconductivity phase appearing at ambient pressure becomes to show complete superconductivity giving zero resistance when the sheet resistance becomes comparable t

Conducting polymer thin films containing inherent structural disorder exhibit complicated electronic, transport, and thermoelectric properties. The unconventional power-law relation between the Seebeck coefficient (<i>S</i>) and the electrical conductivity (σ) is one of the typical consequences of this disorder, where no maximum of the thermoelectric power factor (<i>P</i> = <i>S</i> ²σ) has been observed upon doping, unlike conventional systems. Here, it is demonstrated that a thioph

The Ginzburg-Landau coherence lengths are determined from the temperature dependence of the magnetization by fitting measured results with the renormalization theory of the fluctuation developed for layered superconductors. The derived interlayer coherence lengths are 6±2 Å and 3.2±0.5 Å for κ-(BEDT-TTF) 2 Cu[N(CN) 2 ]Br and κ-(BEDT-TTF) 2 Cu(NCS) 2 , respectively, which are remarkably shorter than the interlayer spacing. It is also found that these coherence lengths are virtually unaffected by

Single-molecule magnets exhibit magnetic bistabililties at the molecular level, making them promising for molecule-based spintronics due to high magnetic densities. The incorporation of SMM behavior and electrical conductivity in one compound is rare because these two physical properties often do not operate in the same temperature range, which further hinders their use in practical applications. Here we present an organic-inorganic molecular hybrid, β″-(BEDO-TTF)₃[Co(pdms)<sub>2</sub

Critical behaviors indicating an insulator–metal (IM) transition are observed in poly(2,5-bis(3-hexadecylthiophene-2-yl)thieno[3,2-b]thiophene) [PBTTT] in ionic-liquid-gated transistors. At room temperature, a maximum channel conductivity of 300 S cm−1 is achieved at the doping concentration of 1021 cm−3. The conductivity shows a very weak temperature dependence; the conductivity at 5 K is only 1.6 times lower than that at 250 K. The signature of the IM transition at low temperatures is evidence

A previously proposed model of rhombohedral PbZr 0.9 Ti 0.1 O 3 (low temperature form) has been confirmed and refined at room temperature. X-ray diffraction data as well as neutron diffraction data of PbZr 0.9 Ti 0.1 O 3 powder have been analysed by profile analysis method. The result is in general agreement with that by Glazer and Mabud, and the structural parameters are now improved considerably. Rather unrealistic temperature parameters found in the previous study are corrected. Oxygen octahe

Abstract Charge transport and thermoelectric conversion mechanisms in doped semicrystalline polymer films are key issues in the field of wearable electronics, whereas the complex film structure consisting of crystalline domains and non-crystalline boundaries prevents sufficient understanding of them. In this study, we fully clarify the roles of the domains and the boundaries in a typical semicrystalline polymer on macroscopic charge transport under continuous electrochemical doping. In the cryst

We study the high-energy behavior of the scattering amplitude and the total scattering cross section for a Dirac operator with a 4 x 4 matrix-valued potential. Moreover, in the electro-magnetic case, it is shown that the electric potential and the magnetic field can be reconstructed from the high-energy behavior of the scattering amplitude. The study of the high-energy behavior of the resolvent estimates is crucial for our proof.

Single-molecule magnets (SMMs) show superparamagnetic behaviour below blocking temperature at the molecular scale, so they exhibit large magnetic density compared to the conventional magnets. Combining SMMs and molecular conductors in one compound will bring about new physical phenomena, however, the synergetic effects between them still remain unexplored. Here we present a layered molecule-based compound, β''-(BEDO-TTF)₄ [Co(pdms)₂]·3H₂O (<b>BO4</b>), (BEDO-TTF