Motoi Kimata

Fermi Surface and Mass Enhancement in KFe2As2 from de Haas-van Alphen Effect Measurements

We report on a band structure calculation and de Haas–van Alphen measurements of KFe 2 As 2 . Three cylindrical Fermi surfaces are found. Effective masses of electrons range from 6 to 18 m e , m e being the free electron mass. Remarkable discrepancies between the calculated and observed Fermi surface areas and the large mass enhancement (({gtrsim}3)) highlight the importance of electronic correlations in determining the electronic structures of iron pnicitide superconductors.

Resistivity and Upper Critical Field in KFe2As2 Single Crystals

Two series of (In1-xFex)(2)O-3 were prepared by a solution combustion method using different fuel to-oxidizer (i.e. glycine/metal nitrate, G/N) ratios. The crystal structure and magnetic properties of the Compounds were investigated by means of X-ray diffraction, transmission electron microscopy and magnetic measurements. Detailed structural analysis shows the solubility limits of Fe in In2O3 are x = 0.08 and 0.45 for the G/N ratios of 5/4 and 5/6, respectively. Crystallite size of the samples prepared with the G/N ratio of 5/6 is much smaller than that of the samples prepared with the G/N ratio of 5/4. At room temperature, the sample with x = 0.01 prepared with the G/N ratio of 5/4 is paramagnetic and those with x = 0.03-0.07 are ferromagnetic, whereas the samples with x = 0.15-0.45 prepared with the G/N ratio of 5/6 show superparamagnetic behavior and those samples with x < 0.15 are paramagnetic. Different magnetic behavior of these two series of samples could be attributed to different origins of magnetism. The magnetism of the samples prepared with the G/N ratio of 5/4 might originate from the existence of mixed valence Fe ions whereas the magnetism of the samples prepared with the G/N ratio of 5/6 could be due to the small crystallite size

Evolution of superconductivity from a charge-density-wave ground state in pressurized (Per)2[Au(mnt)2]

By suppressing the charge density wave ground state in the highly one-dimensional organic conductor (Per)2[Au(mnt)2] with quasi-hydrostatic pressure, a superconducting (SC) phase is established above a pressure of 5u2009kbar. The onset of superconductivity is approximately 300u2009mK and the upper critical field (perpendicular to the perylene stacking axis) is 50u2009mT. The new CDW-SC phase diagram is compared with pressure-induced density wave-SC transitions in other organic compounds.

Fermi Surface in BaNi2P2

We report measurements of the de Haas-van Alphen (dHvA) oscillation and a band structure calculation for the pnictide superconductor BaNi

Quasi-Two-Dimensional Fermi Surfaces and Coherent Interlayer Transport in KFe2As2

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Multi-frequency ESR using a microcantilever in the millimeter wave region

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High-Pressure Electrical Resistivity Measurements of EuFe2As2 Single Crystals

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Pressure-induced antiferromagnetic bulk superconductor EuFe2As2

, which is isostructural to BaFe

Electronic state of magnetic organic conductor (Me-3,5-DIP)[Ni(dmit)2]2

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Anomalous behavior of the dHvA oscillations in CexLa1−xRu2Si2

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