Yuichi Ikuhara

Electrostatic Thermopower Modulation of the KTaO$_3$ Field Effect Transistors (2009)

Yoshikawa, Akira, Uchida, Kosuke, Koumoto, Kunihito, Kato, Takeharu, Ikuhara, Yuichi, Ohta, Hiromichi

We show herein transistor characteristics and field-modulated thermopower for KTaO$_3$ single-crystal based field-effect transistors (FETs), and compare these characteristics with SrTiO$_3$ single...

Selective Detection of Formaldehyde Gas Using a Cd-Doped TiO2-SnO2 Sensor (2009)

Wen Zeng, Tianmo Liu, Zhongchang Wang, Susumu Tsukimoto, Mitsuhiro Saito, Yuichi Ikuhara

We report the microstructure and gas-sensing properties of a nonequilibrium TiO2-SnO2 solid solution prepared by the sol-gel method. In particular, we focus on the effect of Cd doping on the sensing...

Direct observations of Ca ordering in Ca_0.33CoO_2 thin films with different superstructures (2008)

Huang, Rong, Mizoguchi, Teruyasu, Sugiura, Kenji, Ohta, Hiromichi, Koumoto, Kunihito, Hirayama, Tsukasa, ...

Ca-ion superstructures such as sqrt(3)a×sqrt(3)a (hexagonal) and 2a×sqrt(3)a (orthorhombic) in layered Ca_0.33CoO_2 crystalline film, which were prepared by the reactive solid-phase epitaxy and the...

PET fiber fabrics modified with bioactive titanium oxide for bone substitutes (2008)

Kokubo, Tadashi, Ueda, Takahiro, Kawashita, Masakazu, Ikuhara, Yuichi, Takaoka, Gikan H., Nakamura, Takashi

Cross patterning on MgO based on dislocations using femtosecond laser irradiation (2008)

Kanehira, Shingo, Miura, Kiyotaka, Hirao, Kazuyuki, Shibata, Naoya, Ikuhara, Yuichi

Enhanced Seebeck coefficient of quantum-confined electrons in SrTiO_3/SrTi_0.8Nb_0.2O_3 superlattices (2007)

Mune, Yoriko, Ohta, Hiromichi, Koumoto, Kunihito, Mizoguchi, Teruyasu, Ikuhara, Yuichi

We report two-dimensional Seebeck coefficients (|S|_2D) of [(SrTiO_3)x/(SrTi_0.8Nb_0.2O_3)y]_20 (x=1–60, y=1–20) superlattices, which were grown on the (100) face of insulating LaAlO_3 substrates...

Optically produced cross patterning based on local dislocations inside MgO single crystals (2007)

Kanehira, Shingo, Miura, Kiyotaka, Fujita, Koji, Hirao, Kazuyuki, Si, Jinhai, Shibata, Naoya, ...

Site-selectivity of 3d metal cation dopants and dielectric response in calcium copper titanate (2006)

Chung, Sung-Yoon, Choi, Si-Young, Yamamoto, Takahisa, Ikuhara, Yuichi, Kang, Suk-Joong

By doping a few atomic percent of 3d-block cations, we demonstrate that the high dielectric response in CaCu3Ti4O12 can be reduced by a factor of ~103 at room temperature. Each of the added dopants...

Change in cation nonstoichiometry at interfaces during crystal growth in polycrystalline BaTiO3 (2006)

Kang, Suk-Joong L., Choi, Si-Young, Chung, Sung-Yoon, Yamamoto, Takahisa, Ikuhara, Yuichi

Using an embedded single crystal in a polycrystalline matrix and quantitative electron energy loss spectroscopy, we have demonstrated that Ti-excess grain boundary nonstoichiometry can vary with the...

A new method for preparing plan-view TEM specimen of multilayered films using focused ion beam (2004)

Kato, Takeharu, Muroga, Takemi, Iijima, Yasuhiro, Saitoh, Takashi, Yamada, Yutaka, Izumi, Teruo, ...

A new method is proposed for preparing plan-view specimens of a CeO2/Gd2Zr2O7 multilayer on a metal substrate using focused ion beam milling. In the plan-view specimen, a membrane from the...

Identification of crack path of inter- and transgranular fractures in sintered silicon nitride by in situ TEM (2004)

Ii, Seiichiro, Iwamoto, Chihiro, Matsunaga, Katsuyuki, Yamamoto, Takahisa, Ikuhara, Yuichi

Inter- and/or transgranular crack paths in sintered silicon nitride (Si3N4) during fracture were investigated by in situ straining experiments in a transmission electron microscope at room...

Initial growth stage of nanoscaled TiN films: Formation of continuous amorphous layers and thickness-dependent crystal nucleation. (2003)

Li, Tu-Qiang, Noda, Suguru, Komiyama, Hiroshi, Yamamoto, Takahisa, Ikuhara, Yuichi

The initial growth stage of titanium nitride (TiN) deposited by reactive magnetron dc sputtering onto (111)-oriented Si substrates was investigated by using high-resolution transmission electron...

Structure of [110] tilt grain boundaries in zirconia bicrystals (2001)

Shibata, Naoya, Yamamoto, Takahisa, Ikuhara, Yuichi, Sakuma, Taketo

Cubic stabilized zirconia bicrystals with [110] symmetric tilt grain boundaries were fabricated by diffusion bonding of two single crystals with the composition of...

Electron transport behaviour in Nb-doped SrTiO3 bicrystals (2001)

Yamamoto, Takahisa, Ikuhara, Yuichi

In order to elucidate the relationship between electron transport behaviour and defect chemistry, grain boundary structure and current‐voltage characteristics across the boundary were...

Grain boundary structure and chemical bonding state of superplastic SiO2-doped TZP (1997)

Ikuhara, Yuichi, Tanaka, Isao, Thavorniti, Parjaree, Sakuma, Taketo

Superplastic SiO2-doped TZP (tetragonal zirconia polycrystal) was fabricated by sintering at 1300�C in air. The grain boundaries were investigated by high-resolution electron microscopy (HREM),...

Change in Grain Boundary Structure of AIN-Polytype Sialon by Electron Irradiation (1987)

IKUHARA, Yuichi, YOSHINAGA, Hideo

Grain boundary of AIN-polytype Sialon was observed with a high resolution electron microscope. In a grain boundary, there exists a non-crystalline phase of about 1 nm in thickness. By the irradiation...