Takao Shimizu

Since a review on this topic in this Journal appeared (Wolfe, 1982), the CNS has proved to be a major focus in eicosanoid research. Although our knowledge is limited at the moment, the research in this field is rapidly growing. In this short review, we summarize recent progress of research (1982-1989) in this field with special attention directed to eicosanoid metabolism, functions of eicosanoids in the neuroendocrine system and synaptic transmission, current information on eicosanoid receptors,

Ferroelectricity and Curie temperature are demonstrated for epitaxial Y-doped HfO2 film grown on (110) yttrium oxide-stabilized zirconium oxide (YSZ) single crystal using Sn-doped In2O3 (ITO) as bottom electrodes. The XRD measurements for epitaxial film enabled us to investigate its detailed crystal structure including orientations of the film. The ferroelectricity was confirmed by electric displacement filed - electric filed hysteresis measurement, which revealed saturated polarization of 16 μC

PUFAs, such as AA and DHA, are recognized as important biomolecules, but understanding their precise roles and modes of action remains challenging. PUFAs are precursors for a plethora of signaling lipids, for which knowledge about synthetic pathways and receptors has accumulated. However, due to their extreme diversity and the ambiguity concerning the identity of their cognate receptors, the roles of PUFA-derived signaling lipids require more investigation. In addition, PUFA functions cannot be

YO1.5-substituted HfO2 thin films with various substitution amounts were grown on (100) YSZ substrates by the pulsed laser deposition method directly from the vapor phase. The epitaxial growth of film with different YO1.5 amounts was confirmed by the X-ray diffraction method. Wide-area reciprocal lattice mapping measurements were performed to clarify the crystal symmetry of films. The formed phases changed from low-symmetry monoclinic baddeleyite to high-symmetry tetragonal/cubic fluorite phases

Herein, ferroelastic domain switching from the nonpolar b-axis to the polar c-axis oriented domain in 7%-YO1.5-substituted HfO2 (YHO-7) epitaxial ferroelectric films is demonstrated. Scanning transmission electron microscopy (STEM) indicates that the polarization of a pristine film deposited on a Sn-doped In2O3/(001)YSZ substrate by the pulsed laser deposition method tends to be along the in-plane direction to avoid a strong depolarization field with respect to the out-of-plane direction. Applyi

The ferroelectric properties of the (Hf0.5Zr0.5)O2 films on Pt/Ti/SiO2/Si substrate are investigated. It is found that the films crystallized by annealing in O2 and N2 atmospheres have similar crystal structures as well as remanent polarization and coercive fields. Weak temperature and frequency dependences of the ferroelectric properties indicate that the hysteretic behavior in HfO2-based films originates not from the mobile defects but rather from the lattice ionic displacement, as is the case

The effect of the heat treatment conditions on the constituent phases and electrical properties of (Hf0.5Zr0.5)O2 films deposited by the metalorganic chemical vapor deposition was investigated. By using a low temperature or short duration for post-heat treatment after the deposition, the volume fraction of the tetragonal phase increases, resulting in a high dielectric constant. On the other hand, the volume fraction of the monoclinic phase increased in the films that were heat-treated at higher

The crystal structure and ferroelectric properties of 12- to 18 nm-thick epitaxial YO1.5-HfO2 films with 5–9% YO1.5 on (111)ITO//(111)YSZ substrates are investigated to clarify the formation mechanism of the ferroelectric phase. The ferroelectric orthorhombic phase can be obtained by transformation from the higher symmetric tetragonal phase by surmounting a relatively low energy barrier. The orthorhombic phase is obtained for 6% and 7% YO1.5-doped HfO2 films by heat treatment at 1000 °C. Althoug

The ferroelectric phase transformation from the tetragonal phase to the orthorhombic phase, induced by an electric field, is demonstrated in a 5%YO 1.5 ‐doped Hf 0.5 Zr 0.5 O 2 epitaxial film which is grown on Sn‐doped In 2 O 3 ‐covered (111) yttria‐stabilized zirconia by the pulsed laser deposition method at room temperature and subsequent heat treatment. Although X‐ray diffraction shows the film to consist of a paraelectric tetragonal phase after the heat treatment, polarization–electric field

An increase of the Curie temperature, TC, was demonstrated for BaTiO3 (BTO) epitaxial thin films grown by a pulsed laser deposition technique on (001) and (110) SrTiO3 (STO) substrates. The T(C) values for the BTO films on (001) and (110) STO were determined, from the temperature dependence of the lattice constants, to be 720 and 550 K, respectively, both of which are higher than that for bulk BTO. The increase of T(C) for the film on (001) BTO is suggested to stem from a large tetragonal deform