Nagoya Institute of Technology

About: Nagoya Institute of Technology is a education organization based out in Nagoya, Japan. It is known for research contribution in the topics: Thin film & Catalysis. The organization has 10766 authors who have published 19140 publications receiving 255696 citations. The organization is also known as: Nagoya Kōgyō Daigaku & Nitech.

The Effect of MgO and Rare-Earth Oxide on Formation Behavior of Core-Shell Structure in BaTiO3

Abstract: The formation mechanism of the core-shell structure of a BaTiO3(BT)–MgO–Ho2O3-based system was studied. Mg reacted with BT at low temperatures and showed poor diffusivity compared with Ho. The core-shell structure was considered to be formed by the suppression of the diffusion of Ho into the core region by Mg. Also, replacement modes of Mg and Ho in perovskite were investigated. Lattice parameters were determined at temperatures higher than the Curie temperature in order to avoid crystal structure change. It was confirmed that Mg dissolved in Ti site, and Ho dissolved in both Ba and Ti sites. This indicates that Mg ions act as acceptors and Ho ions act as both donors and acceptors in the shell phase.

New Insight into Structural Evolution in Layered NaCrO2 during Electrochemical Sodium Extraction

Abstract: Electrochemical properties and structural changes during charge for NaCrO2, whose structure is classified as α-NaFeO2 type layered polymorph (also O3-type following the Delmas’ notation), are examined as a positive electrode material for nonaqueous Na-ion batteries. NaCrO2 delivers initial discharge capacity of 110 mAh g–1 at 1/20C rate in the voltage range of 2.5–3.6 V based on reversible Cr3+/Cr4+ redox without oxidation to hexavalent chromium ions, while the initial discharge capacity is only 9 mAh g–1 when cutoff voltage is set to 4.5 V. Results from ex-situ X-ray diffraction, X-ray absorption spectroscopy, and DFT calculations reveal that the irreversible phase transition occurs after sodium extraction by charging over a voltage plateau at 3.8 V associated with the lattice shrinkage along the c-axis in the case of x > 0.5 in Na1–xCrO2, which originates from the migration of chromium ions from octahedral sites in CrO2 slabs to both tetrahedral and octahedral sites in interslab layer. The irreversible ...

Three-dimensional chiral molecule-based ferrimagnet with triple-helical-strand structure.

Abstract: Dark orange, hexagonal prism crystals of [Cr(CN)6] [Mn Dor L-NH2ala]3·(3H2O) were obtained by slow diffusion of MnCl2·4H2O (1.7 mmol), Dor L-aminoalanine hydrochloride (Dor L-NH2alaH·HCl, 2.6 mmol), and KOH (5.2 mmol) in H2O into K3[Cr(CN)6] (1.5 mmol) in H2O/iso-propanol (1:1) mixture under argon atmosphere after several weeks. X-ray crystal structure analyses of Dand L-isomers at 100 K reveal that compounds (1) crystallize in the chiral space group, hexagonal P63, and consist of leftand right-handed helical structures of MnII ions, respectively (Figure 1). Each aminoalanine ion employs two types of functional groups to bridge between two adjacent MnII ions (Mn– Mn separation is 5.923 Å.). Two amino moieties and one carboxyl group within the aminoalanine ion are coordinated to two MnII ions in monodentate and bidentate coordination mode, respectively. This unique coordination leads to the construction of two differing chelating rings around the MnII ion: fiveand six-membered rings. These rings align alternately resulting in the generation of extended helical chains along the c-axis. As expected, self-assemblies are formed between helical chains to aggregate three helical chains (Figure 2), in which the shortest Mn–Mn separation between chains is 6.517 Å. The channel structure is generated and disordered water molecules exist in the center of the triple helical strand structure (on the screw axis). On the other hand, each [Cr(CN)6] ion utilizes all cyanide moieties to connect between adjacent strands via cyanide bridges to MnII ions; as a result, a threedimensional cyanide network is formed. The shortest and longest adjacent Cr–Mn distances through cyanide bridges are 5.490 and 5.508 Å, respectively, which are slightly longer than those in the previous crystals. The cyanide bridged network also displays basic units comprised of a helical strand structure. Each cyanidebridged helical strand, which is composed of four metal centers (two MnII and two CrIII ions) and four cyanide groups as a repeating unit characterized by a reverse turn within the helical strand of MnII and NH2ala ions along the c-axis, shares the apex of the helical strand (CrIII ion) between three adjacent helical strands (Figure 1). This compound exhibits ferrimagnetic behavior essentially below 35 K. The magnetic transition temperature of this compound is relatively low despite formation of a three-dimensional cyanide network. This phenomenon is probably attributable to the comparatively long cyanide-bridged distance in this crystal. In addition, it may result consequent to the occurrence of spin frustration between manganese ions within the triple helical strand at high temperature. Below 35 K, the spin on manganese alone survives due to the ferrimagnetic coupling between manganese and chromium ions. From a physical standpoint, this phenomenon is the focus of interesting research, as the spin structure of this compound is also expected to possess triple helical nature. Some chiral molecule-based magnets have been prepared previously; however, at present, a chiral helical spin structure has not been documented. It is one of the reasons affording an explanation as to why a crystal forming a helical structure has never been synthesized. Thus, it is certain that this molecule is a suitable candidate for this endeavor. Magnetization measurements, μSR (muon spin resonance) spectroscopy and neutron diffraction of a single crystal will lead 115 Annual Review 2004

Measurement of the parameters of the mass transfer kinetics in high performance liquid chromatography

Abstract: Fundamental studies of the mass transfer kinetics are as essential as those of the retention equilibrium for a detailed understanding of the characteristics and the mechanisms of chromatographic separations. The acquisition of a large amount of reliable experimental data and of meaningful results is necessary for any further progress of our knowledge of kinetics. The main goal of this review is to provide information on the methods used to perform accurate measurements and on the data analysis procedures used for deriving the kinetic parameters characterizing mass transfer in HPLC. First, the general characteristics of several methods of determination of some kinetic parameters are briefly reviewed. Secondly, we give detailed explanations of the experimental conditions of the pulse on a plateau method (i.e., elution chromatography on a plateau of finite concentration or pulse response method) and of the data analysis procedures based on moment analysis. Thirdly, we explain some important requirements for the acquisition of appropriate experimental data and discuss corrections to be applied when deriving several kinetic parameters. Fourthly, we discuss the accuracy of the kinetic parameters derived from the pulse on a plateau method and from moment analysis. Finally, some results concerning the mass transfer kinetics in RPLC systems are demonstrated as examples.