Microscopic Model and Phase Diagrams of the Multiferroic Perovskite Manganites (2009)
Mochizuki, Masahito, Furukawa, Nobuo
Orthorhombically distorted perovskite manganites, RMnO3 with R being a trivalent rare-earth ion, exhibit a variety of magnetic and electric phases including multiferroic (i.e. concurrently magnetic...
Mochizuki, Masahito, Furukawa, Nobuo
Magnetoelectric phase diagrams of the perovskite manganites, Eu1-xYxMnO3 and Gd1-xTbxMnO3, are theoretically studied. We first construct a microscopic model, and then analyze the model using the...
Precise Control of Band Filling in NaxCoO2 (2007)
Yoshizumi, Daisuke, Muraoka, Yuji, Okamoto, Yoshihiko, Kiuchi, Yoko, Yamaura, Jun-Ichi, Mochizuki, Masahito, ...
Electronic properties of the sodium cobaltate NaxCoO2 are systematically studied through a precise control of band filling. Resistivity, magnetic susceptibility and specific heat measurements are...
Mochizuki, Masahito, Yuan, H. Q., Ogata, Masao
Several thermodynamic measurements for the cobaltate superconductor, NaxCoO2.yH2O, have so far provided results inconsistent with each other. In order to solve the discrepancies, we microscopically...
Mochizuki, Masahito, Ogata, Masao
In order to understand the experimentally proposed phase diagrams of NaxCoO2.yH2O, we theoretically study the CoO2-layer-thickness dependence of magnetic and superconducting (SC) properties by...
Mochizuki, Masahito, Ogata, Masao
Motivated by recently reported experimental phase diagrams, we study the effects of CoO6 distortion on the electronic structure in NaxCoO2.yH2O. We construct the multiband tight-binding model by...
Yanase, Youichi, Mochizuki, Masahito, Ogata, Masao
The possibility of multiple phase diagram in the novel superconductor Na_{x}CoO_{2}yH_{2}O is analyzed on the basis of the multi-orbital Hubbard model including the atomic spin-orbit coupling. We...
Yanase, Youichi, Mochizuki, Masahito, Ogata, Masao
The d-vector in possibile spin triplet superconductor Na_{x}CoO_{2}yH_{2}O is microscopically investigated on the basis of the multi-orbital Hubbard model including the atomic spin-orbit coupling. As...
Mochizuki, Masahito, Yanase, Youichi, Ogata, Masao
In the recently discovered Co-oxide superconductor Na_xCoO_2*yH_2O, the edge-shared CoO6 octahedra are trigonally contracted along the c-axis in the CoO2-plane. We study how this CoO6 distortion...
Mochizuki, Masahito, Yanase, Youichi, Ogata, Masao
Spin and charge fluctuations and superconductivity in Na_0.35CoO_2*1.3H_2O are studied based on a multi-orbital Hubbard model. By applying the fluctuation exchange (FLEX) approximation, we show that...
Orbital Physics in the Perovskite Ti Oxides (2004)
Mochizuki, Masahito, Imada, Masatoshi
In the perovskite Ti oxide RTiO3 (R=rare-earth ions), the Ti t2g orbitals and spins in the 3d^1 state couple each other through the strong electron correlations, resulting in a rich variety of...
Multi-orbital analysis on the Superconductivity in Na_{x}CoO_{2} \cdot y H_{2}O (2004)
Yanase, Youichi, Mochizuki, Masahito, Ogata, Masao
We preform a multi-orbital analysis on the novel superconductivity in Na_{x}CoO_{2} \cdot yH_{2}O. We construct a three-orbital model which reproduces the band structure expected from the LDA...
Mochizuki, Masahito, Yanase, Youichi, Ogata, Masao
Spin and charge fluctuations and superconductivity in a recently discovered superconductor Na_xCoO_2*yH_2O are studied based on a multi-orbital Hubbard model. Tight-binding parameters are determined...
Mochizuki, Masahito, Imada, Masatoshi
The origin of the antiferromagnetic order and puzzling properties of LaTiO_3 as well as the magnetic phase diagram of the perovskite titanates are studied theoretically. We show that in LaTiO_3, the...
Orbital-Spin Structure and Coupling to Lattice in RTiO$_3$ with R=La,Pr,Nd and Sm (2003)
Mochizuki, Masahito, Imada, Masatoshi
The origin of the G-type antiferromagnetism (AFM(G)) and puzzling properties of RTiO$_3$ with R=La are studied. We clarify that the crystal field from La caused by the GdFeO$_3$-type distortion lifts...
The magnetic phase diagram of the perovskite-type Ti oxides as a function of the GdFeO3-type distortion is examined by using the Hartree-Fock analysis of a multiband d-p Hamiltonian from a viewpoint...
Origin of G-type Antiferromagnetism and Orbital-Spin Structures in ${\rm LaTiO}_3$ (2001)
Mochizuki, Masahito, Imada, Masatoshi
The possibility of the $D_{3d}$ distortion of ${\rm TiO}_6$ octahedra is examined theoretically in order to understand the origin of the G-type antiferromagnetism (AFM(G)) and experimentally observed...
Mochizuki, Masahito, Imada, Masatoshi
The properties and mechanism of the magnetic phase transition of the perovskite-type Ti oxides, which is driven by the Ti-O-Ti bond angle distortion, are studied theoretically by using the effective...
Magnetic Phase Transition of the Perovskite-type Ti Oxides (2000)
Mochizuki, Masahito, Imada, Masatoshi
Properties and mechanism of the magnetic phase transition of the perovskite-type Ti oxides, which is driven by the Ti-O-Ti bond angle distortion, are studied theoretically by using the effective spin...
影響関数法および固有ひずみ解析法による溶接残留応力場における表面き裂の応力拡大係数の評価 (1999)
宮崎, 克雅, 菅野, 智, 望月, 正人, 林, 眞琴, 白鳥, 正樹, 于, 強, ...
Stress intensity factor due to surface crack propagation was analyzed by using the Influence function method and inherent strain analysis of residual stress fields caused by welding. Initial residual...