We have successfully synthesized the series of the double-perovskite R2CoMnO6 (R  =  rare earth: La to Lu) single crystals and have investigated their magnetic properties. The ferromagnetic order of Co(2+)/Mn(4+) spins emerges mainly along the c axis. Upon decreasing the size of rare earth ion, the magnetic transition temperature decreases linearly from 204 K for La2CoMnO6 to 48 K for Lu2CoMnO6, along with the enhancement of monoclinic distortion. The temperature and magnetic-field dependences of magnetization reveal the various magnetic characteristics such as the metamagnetic transition in R  =  Eu, the isotropic nature of rare earth moment in R  =  Gd, and the reversal of magnetic anisotropy in R  =  Tb and Dy. Our results offer comprehensive information for understanding the roles of mixed-valent magnetic ions and rare earth magnetic moments on the magnetic properties.

From these results, we conclude that urinary phyto-oestrogens, especially enterolactone and apigenin, are related to BMD in Korean postmenopausal women. Our results also suggest the possibility that phyto-oestrogens have differential effects on bone density. Further studies are needed to clarify the exact biological roles of phyto-oestrogenic components on bone metabolism.

The magnetocaloric effect (MCE) is described by the change in temperature of a material by magnetic field variation and is a crucial subject in magnetism; it is motivated by the desire to enhance energy-efficient magnetic refrigeration for clean technology. Despite the recent discovery of the giant cryogenic MCE in double perovskites, the role of magnetic anisotropy has not yet been clearly discussed, because of the averaging effect of polycrystalline samples. Here, we investigated the anisotropic MCE in the single-crystal double perovskite Gd2CoMnO6. In addition to the ferromagnetic order of the Co2+ and Mn4+ moments, the large Gd3+ moments align below T Gd = 21 K, exhibiting an isotropic nature. Because of the intricate temperature development of magnetically hysteretic behaviour and metamagnetism, the change in magnetic entropy along the c-axis appears to be relatively small. On the contrary, the smaller but almost reversible magnetization perpendicular to the c-axis leads to a large MCE with a maximum entropy change of 25.4 J/kg·K. The anisotropic MCE generates a giant rotational MCE, estimated as 16.6 J/kg·K. Our results demonstrate the importance of magnetic anisotropy for understanding the MCE and reveal essential clues for exploring suitable magnetic refrigerant compounds aiming at magnetic functional applications.

We obtained the spectral function of very high quality natural graphite single crystals using angle resolved photoelectron spectroscopy (ARPES). A clear separation of non-bonding and bonding bands and asymmetric lineshape are observed. The asymmetric lineshapes are well accounted for by the finite photoelectron escape depth and the band structure. The extracted width of the spectral function (inverse of the photohole life time) near the K point is, beyond the maximum phonon energy, approximately proportional to the energy as expected from the linear density of states near the Fermi energy. The upper bound for the electron-phonon coupling constant is about 0.2, a much smaller value than the previously reported one.PACS numbers: 74.25.Jb, 63.20.Ls, Recent discoveries of novel physical properties in carbon-based materials such as superconductivity 1,2,3,4,5 and massless Dirac Fermions 6 brought renewed interest in the electronic structure of graphite 7,8 . The peculiarity of the electronic structure of graphite has two aspects: graphite is extremely two dimensional and is a semi-metal. These facts make it fundamentally interesting to study how dimensionality affects the dynamics of the doped carriers and how the carriers in graphite intercalated compounds (GICs) couple to the mediating bosons. In fact, there is a long standing issue in regards to the carrier dynamics in graphite, that is, whether the carriers are Fermi-liquid-like or not. This question motivates experimental studies of electronic structures of these materials by using, for example, angle-resolved photoemission spectroscopy (ARPES) and one can find a long history in the ARPES studies on graphite single crystals 7,8,9,10,11,12,13,14,15 . In addition, studies of graphite-related materials such as single 16 and bilayer graphene 17 and GICs 18,19 can be found.High quality ARPES data from graphite is difficult to obtain despite graphite's two dimensional, inert nature. The problems associated with ARPES experiments on graphite are due mostly to difficulty in proper surface preparation and to some extent to the low quality of the single crystals. For example, the extreme twodimensional nature of graphite inevitably produces small flakes (many are small enough to be seen only under microscopes) on the cleaved surfaces which ruins the momentum resolution in ARPES. Such difficulties prevented one from obtaining good quality data to extract reliable information on the many-body interactions such as electron-phonon coupling (EPC). Therefore, unless such difficulties are overcome, reliable information on manybody interactions can not be extracted from the data. As a result, the experimental data in regards to the electron lifetime have been obtained mostly by time-resolved photoelectron spectroscopy on highly oriented pyrolytic graphite 20,21 .Motivated by the renewed interest in the carrier dynamics in graphite, we have performed ARPES studies on graphite single crystals. Our goal was to extract reliable quantitative information on the EPC from ARPES data. To ...

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