Magnetism and superconductivity in CeRh_{1-x}Ir_xIn_5 heavy fermion materials

We report on zero-field muon spin relaxation studies of cerium based heavy-fermion materials CeRh_{1-x}Ir_xIn_5. In the superconducting x=0.75 and 1 compositions muon spin relaxation functions were found to be temperature independent across T_c; no evidence for the presence of electronic magnetic moments was observed. The x=0.5 material is antiferromagnetic below T_N=3.75 K and superconducting below T_c=0.8 K. Muon spin realxation spectra show the gradual onset of damped coherent oscillations characteristic of magnetic order below T_N. At 1.65 K the total oscillating amplitude accounts for at least 85% of the sample volume. No change in muon precession frequency or amplitude is detected on cooling below T_c, indicating the microscopic coexistence of magnetism and superconductivity in this material.Comment: 6 pages with 3 figures. Revision with corrected axis label (mK) in Fig.

気管支喘息関連遺伝子領域の17q21領域は日本人アレルギー性鼻炎にも関連する

以下に掲載：Allergy: European Journal of Allergy and Clinical Immunology 68(1) pp.92-100 2013. John Wiley & Sons. 共著者：K Tomita, M Sakashita, T Hirota, S Tanaka, K Masuyama, T Yamada, S Fujieda, A Miyatake , N Hizawa, M Kubo, Y Nakamura, M Tamar

First Principles Calculation of Anomalous Hall Conductivity in Ferromagnetic bcc Fe

We perform a first principles calculation of the anomalous Hall effect in ferromagnetic bcc Fe. Our theory identifies an intrinsic contribution to the anomalous Hall conductivity and relates it to the k-space Berry phase of occupied Bloch states. The theory is able to account for both dc and magneto-optical Hall conductivities with no adjustable parameters.Comment: 4 pages, 6 figures, author list correcte

Carrier-Induced Magnetic Circular Dichloism in the Magnetoresistive Pyrochlore Tl2Mn2O7

Infrared magnetic circular dichloism (MCD), or equivalently magneto-optical Kerr effect, has been measured on the Tl2Mn2O7 pyrochlore, which is well known for exhibiting a large magnetoresistance around the Curie temperature T_C ~ 120 K. A circularly polarized, infrared synchrotron radiation is used as the light source. A pronounced MCD signal is observed exactly at the plasma edge of the reflectivity near and below T_c. However, contrary to the conventional behavior of MCD for ferromagnets, the observed MCD of Tl2Mn2O7 grows with the applied magnetic field, and not scaled with the internal magnetization. It is shown that these results can be basically understood in terms of a classical magnetoplasma resonance. The absence of a magnetization-scaled MCD indicates a weak spin-orbit coupling of the carriers in Tl2Mn2O7. We discuss the present results in terms of the microscopic electronic structures of Tl2Mn2O7.Comment: 5 pages, 5 figures, submitted to J. Phys. Soc. Jp

Unusual landing of deepsea lobster Palinustus waguensis at Cuddalore

Deepsea blunt horn lobster, Palinustus waguensis Kubo,1963 was landed by bottom set gillnets operated at Cuddalore during July 2011. Their occurrence has been reported earlier in the deepsea trawl landings at Kasimedu, Chenna

Magnetic order and frustrated dynamics in Li(Ni0.8Co0.1Mn0.1)O2: a study by {\mu}+SR and SQUID magnetometry

Recently, the mixed transition metal oxides of the form Li(Ni1-y-zCoyMnz)O2, have become the center of attention as promising candidates for novel battery material. These materials have also revealed very interesting magnetic properties due to the alternate stacking of planes of metal oxides on a 2D triangular lattice and the Li-layers. The title compound, Li(Ni0.8Co0.1Mn0.1)O2, has been investigated by both magnetometry and measurements and {\mu}+SR. We find the evolution of localized magnetic moments with decreasing temperature below 70 K. The magnetic ground state (T = 2 K) is, however, shown to be a frustrated system in 3D, followed by a transition into a possible 2D spinglass above 22 K. With further increasing temperature the compound show the presence of remaining correlations with increasing effective dimensionality all the way up to the ferrimagnetic transition at TC = 70 K.Comment: Accepted for publication in Physics Procedia (muSR2011 Conference

Giant Magnetoresistance Effect in the Metal-Insulator Transition of Pyrochlore Oxide Nd2Ir2O7

We investigated the magnetoresistance (MR) effect of the pyrochlore oxide Nd2Ir2O7, which shows a metal-insulator transition at T_MI =33 K. A small positive MR effect was observed in the metallic state above T_MI, while a large negative MR effect was observed in the insulating state below T_MI . MR effects exceeding 3000% were found at 1 K at a field of 9 T. As a result, we confirmed the crossover from the insulating state to a state with a small or partial band gap in a field up to 56 T. Furthermore, from the MR effect in Eu2Ir2O7 (T_MI = 120 K) and Gd$_2$Ir$_2$O$_7$ (T_MI = 127 K), we revealed that the large negative MR effect of the pyrochlore iridate Ln2Ir2O7 depends on the magnetism of the lanthanide Ln^{3+} ion. The d-f interaction plays a significant role in the large negative MR effect in the insulating state.Comment: 10 pages, 4 figure