Y. Moritomo

Publication List Details

Period

1995 - 2006

Number

33

Co-Authors

Enhanced Optical Gap in Bi-layered Manganites La$_{2-2x}$Sr$_{1+2x}$Mn$_{2}$O$_{7}$ near $x=0.4$ (2006)

Kim, Myung Whun, Lee, H. J., Yang, B. J., Kim, Kee Hoon, Moritomo, Y., Yu, Jaejun, ...

We have systematically investigated the optical conductivity spectra of La$_{2-2x}$Sr$_{1+2x}$Mn$_{2}$O$_{7}$ ($0.3 \leqslant x \leqslant 0.5$). We find that just above the magnetic ordering...

Nano-magnetic droplets and implications to orbital ordering in La1-xSrxCoO3 (2005)

Phelan, D., Louca, Despina, Rosenkranz, S., Qiu, Y., Chupas, P. J., ...

Inelastic cold neutron scattering on LaCoO3 provided evidence for a distinct low energy excitation at 0.6 meV coincident with the thermally induced magnetic transition. Coexisting strong...

Unusual electron-doping effects in Sr$_{2-x}$La$_x$FeMoO$_6$ observed by photoemission spectroscopy (2005)

Saitoh, T., Nakatake, M., Nakajima, H., Morimoto, O., Kakizaki, A., Xu, Sh., ...

We have investigated the electronic structure of electron-doped Sr$_{2-x}$La$_x$FeMoO$_6$ ($x$=0.0 and 0.2) by photoemission spectroscopy and band-structure calculations within the local-density...

Pressure/temperature/substitution-induced melting of A-site charge disproportionation in Bi_(1-x)La_(x)NiO_3 (0 =< x =< 0.5) (2005)

Ishiwata, S., Azuma, M., Hanawa, M., Moritomo, Y., Ohishi, Y., Kato, K., ...

Metal-insulator transitions strongly coupled with lattice were found in Bi1-xLaxNiO3. Synchrotron X-ray powder diffraction revealed that pressure (P ~ 3 GPa, T = 300 K), temperature (T ~ 340 K, x =...

Resonant inelastic x-ray scattering study of hole-doped manganites La1-xSrxMnO3 (x=0.2 and 0.4) (2004)

Ishii, K., Inami, T., Ohwada, K., Kuzushita, K., Mizuki, J., Murakami, Y., ...

Electronic excitations near the Fermi energy in the hole doped manganese oxides (La1-xSrxMnO3, x=0.2 and 0.4) have been elucidated by using the resonant inelastic x-ray scattering (RIXS) method. A...

Universal features of charge and spin order in a half-doped layered perovskite (2003)

Zaliznyak, I. A., Tranquada, J. M., Gu, G., Erwin, R. W., Moritomo, Y.

We have investigated the peculiar structure of charge and spin ordering in the half-doped layered perovskite oxide La$_{1.5}$Sr$_{0.5}$CoO$_4$ by elastic neutron scattering. Two samples with...

Spin/Orbital Pattern-Dependent Polaron Absorption in Nd(1-x)Sr(x)MnO3 (2002)

Kim, M. W., Jung, J. H., Kim, K. H., Lee, H. J., Yu, Jaejun, Noh, T. W., ...

We investigated optical properties of Nd(1-x)Sr(x)MnO3 (x= 0.40, 0.50, 0.55, and 0.65) single crystals. In the spin/orbital disordered state, their conductivity spectra look quite similar, and the...

Highly Degenerate Canted Spin Structure in Bilayer Manganite La$_{1.1}$Sr$_{1.9}$Mn$_2$O$_7$ (2001)

Kubota, M., Oohara, Y., Yoshizawa, H., Fujioka, H., Hirota, K., Moritomo, Y., ...

We have examined magnetic ordering of the two-dimensional (2D) bilayer manganite La$_{1.1}$Sr$_{1.9}$Mn$_2$O$_7$ with neutron diffraction technique. Due to the two-dimensionality, there appears...

Spin-entropy driven melting of the charge order in La1.5Sr0.5CoO4 (2001)

Zaliznyak, I. A., Tranquada, J. M., Erwin, R., Moritomo, Y.

We studied the melting of the charge order in the half-doped tetragonal perovskite La1.5Sr0.5CoO4 by elastic neutron scattering. We found that diffuse peaks, corresponding to the breathing-type...

Effects of transition metal doping in MgB$_2$ superconductor (2001)

Moritomo, Y., Xu, Sh.

Effects of chemical substitution of the divalent transition metals has been systematically investigated in Mg$_{1-x}M_x$B$_2$ (x=0.03; M=Mn, Fe, Co, Ni and Zn). Substitution of magnetic ions, i.e.,...

Spin dynamical properties and orbital states of the layered perovskite La_2-2x_Sr_1+2x_Mn_2_O_7 (0.3 (2001)

Hirota, K., Ishihara, S., Fujioka, H., Kubota, M., Yoshizawa, H., Moritomo, Y., ...

Low-temperature spin dynamics of the double-layered perovskite La_2-2x_Sr_1+2x_Mn_2_O_7 (LSMO327) was systematically studied in a wide hole concentration range (0.3

Observation of anomalous single-magnon scattering in half-metallic ferromagnets by chemical pressure control (2000)

Akimoto, T., Moritomo, Y., Nakamura, A., Furukawa, N.

Temperature variation of resistivity and specific heat have been measured for prototypical half-metallic ferromagnets, R_0.6Sr_0.4MnO_3, with controlling the one-electron bandwidth W. We have found...

Magnon scattering processes and low temperature resistivity in CMR manganites (2000)

Furukawa, N., Shimomura, Y., Akimoto, T., Moritomo, Y.

Low temperature resistivity of CMR manganites is investigated. At the ground state, conduction electrons are perfectly spin polarized, which is called half-metallic. From one-magnon scattering...

Competition of charge, orbital, and ferromagnetic correlations in layered manganites (2000)

Romero, D. B., Moritomo, Y., Mitchell, J. F., Drew, H. D.

The competition of charge, orbital, and ferromagnetic interactions in layered manganites is investigated by magneto-Raman scattering spectroscopy. We find that the colossal magnetoresistance effect...

Independent freezing of charge and spin dynamics in La1.5Sr0.5CoO4 (2000)

Zaliznyak, I. A., Hill, J. P., Tranquada, J. M., Erwin, R., Moritomo, Y.

We present elastic and quasielastic neutron scattering measurements characterizing peculiar short-range charge-orbital and spin order in the layered perovskite material La1.5Sr0.5CoO4. We find that...

Influence of Quasi-Bi-Stripe Charge Order on the Resistivity and Magnetism in a Bilayer Manganite La$_{2-2x}$Sr$_{1+2x}$Mn$_{2}$O$_{7}$ (2000)

Kubota, M., Oohara, Y., Yoshizawa, H., Fujioka, H., Shimizu, K., Hirota, K., ...

The charge ordering in the bilayer manganite system La$_{2-2x}$Sr$_{1+2x}$Mn$_{2}$O$_{7}$ with $0.30 \le x \le 0.50$ has been studied by neutron diffraction. The charge order is characterized by the...

Magnetic Field Dependent Optical Studies of a Layered Antiferromagnet Pr$%_{1/2}$Sr$_{1/2}$MnO$_3$ (2000)

Jung, J. H., Lee, H. J., Noh, T. W., Moritomo, Y., Wang, Y. J., Wei, X.

Magnetic field ($H$)-dependent optical conductivity spectra $\sigma (\omega) $ and dielectric constant spectra $\epsilon (\omega)$ of a layered antiferromagnet ($A$-type) Pr$_{1/2}$Sr$_{1/2}$MnO$_3$...

Melting of Charge/Orbital Ordered States in Nd$_{1/2}$Sr$_{1/2}$MnO$_3$: Temperature and Magnetic Field Dependent Optical Studies (1999)

Jung, J. H., Lee, H. J., Noh, T. W., Choi, E. J., Moritomo, Y., Wang, Y. J., ...

We investigated the temperature ($T=$ 15 $\sim $ 290 K) and the magnetic field ($H=$ 0 $\sim $ 17 T) dependent optical conductivity spectra of a charge/orbital ordered manganite,...

Temperature-Dependent Pseudogaps in Colossal Magnetoresistive Oxides (1999)

Saitoh, T., Dessau, D. S., Moritomo, Y., Kimura, T., Tokura, Y., Hamada, N.

Direct electronic structure measurements of a variety of the colossal magnetoresistive oxides show the presence of a pseudogap at the Fermi energy E_F which drastically suppresses the electron...

Dimensional Crossover driven by Magnetic Ordering in Optical Conductivity of Pr_{1/2}Sr_{1/2}MnO_3 (1999)

Jung, J. H., Choi, E. J., Lee, H. J., Yu, Jaejun, Moritomo, Y., Noh, T. W.

We investigated optical properties of Pr_{0.5}Sr_{0.5}MnO_3, which has the A-type antiferromagnetic ordering at a low temperature. We found that T- dependence of spectral weight transfer shows a...

Optical spectra measured on cleaved surfaces of double-exchange ferromagnet La1-xSrxMnO3 (1999)

Takenaka, K., Iida, K., Sawaki, Y., Sugai, S., Moritomo, Y., Nakamura, A.

Optical reflectivity spectra were measured on cleaved surfaces of La1-xSrxMnO3 single crystals (x=0.175, T_C=283 K) over a temperature range 10-295 K. The optical conductivity $sigma(\omega)$ shows,...

Optical Investigations of Charge Gap in Orbital Ordered La1/2Sr3/2MnO4 (1999)

Jung, J. H., Ahn, J. S., Noh, T. W., Lee, Jinhyoung, Yu, Jaejun, Moritomo, Y., ...

Temperature and polarization dependent electronic structure of La1/2Sr3/2MnO4 were investigated by optical conductivity analyses. With decreasing temperature, for E//ab, a broad mid-infrared (MIR)...

Relation between crystal and magnetic structures of the layered manganites La2-2xSr1+2xMn2O7 (0.30 =< x =< 0.50) (1999)

Kubota, M., Fujioka, H., Hirota, K., Ohoyama, K., Moritomo, Y., Yoshizawa, H., ...

Comprehensive neutron-powder diffraction and Rietveld analyses were carried out to clarify the relation between the crystal and magnetic structures of La2-2xSr1+2xMn2O7 (0.30 =< x =< 0.50). The...

Spin Dynamical Properties of the Layered Perovskite La1.2Sr1.8Mn2O7 (1999)

Fujioka, H., Kubota, M., Hirota, K., Yoshizawa, H., Moritomo, Y., Endoh, Y.

Inelastic neutron-scattering measurements were performed on a single crystal of the layered colossal magnetoresistance (CMR) material La1.2Sr1.8Mn2O7 (Tc ~ 120K). We found that the spin wave...

Neutron Scattering Studies on Magnetic Structure of the Double-Layered Manganite La_{2-2x}Sr_{1+2x}Mn_2O_7 ($0.30 \leq x \leq 0.50$) (1999)

Kubota, M., Fujioka, H., Ohoyama, K., Hirota, K., Moritomo, Y., Yoshizawa, H., ...

Systematic powder diffraction studies have been carried out to establish the magnetic phase diagram of La_{2-2x}Sr_{1+2x}Mn_2O_7 (LSMO327) in a wide hall concentration range ($0.30 \leq x \leq...

Interplay of the CE-type charge ordering and the A-type spin ordering in a half-doped bilayer manganite La{1}Sr{2}Mn{2}O{7} (1998)

Kubota, M., Yoshizawa, H., Moritomo, Y., Fujioka, H., Hirota, K., Endoh, Y.

We demonstrate that the half-doped bilayer manganite La_{1}Sr_{2}Mn_{2}O_{7} exhibits CE-type charge-ordered and spin-ordered states below $T_{N, CO}^A = 210$ K and below $T_{N}^{CE} \sim 145$ K,...

Soft x-ray magnetic circular dichroism study of the colossal magnetoresistance compound La1-xSrxMnO3 (1997)

Pellegrin, E., Tjeng, L.H., Hesper, R., Sawatzky, G.A., Moritomo, Y., ...

Soft X-ray magnetic circular dichroism (SXMCD) measurements are reported on the O K- and Mn L-absorption edges of La1-x Srx MnO3 (x = 0.15, 0.18, and 0.4) single crystals in their ferromagnetic...

Magnetism and Structural Distortion in the La0.7Sr0.3MnO3 Metallic Ferromagnet (1995)

Martin, Michael C., Shirane, G., Endoh, Y., Hirota, K., Moritomo, Y., Tokura, Y.

Neutron scattering studies on a single crystal of the highly-correlated electron system, La1-xSrxMnO3 with x~0.3, have been carried out elucidating both the spin and lattice dynamics of this metallic...