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991.
Huang SW Huang DJ Okamoto J Mou CY Wu WB Yeh KW Chen CL Wu MK Hsu HC Chou FC Chen CT 《Physical review letters》2008,101(7):077205
Based on resonant soft x-ray magnetic scattering, we report that LiCu2O2 exhibits a large interchain coupling which suppresses quantum fluctuations along spin chains, and a quasi-2D short-range magnetic order prevails at temperatures above the magnetic transition. These observations unravel the fact that the ground state of LiCu2O2 possesses long-range 2D-like incommensurate magnetic order rather than being a gapped spin liquid as expected from the nature of quantum spin-1/2 chains. In addition, the spin coupling along the c axis is found to be essential for inducing electric polarization. 相似文献
992.
H. Fujishita S. Murakami N. Nakamura Y. Kanou H. Okamoto 《Solid State Communications》2008,145(5-6):246-249
The lattice parameters of La1.85Sr0.15CuO4 were measured by an x-ray Rietveld method between 15 K and room temperature. A change in a lattice parameter could be detected at superconducting phase transition. It is pointed out, for the first time, that the change can be attributed to a spontaneous strain in the superconducting phase caused by coupling between a superconducting order parameter and the strain. 相似文献
993.
S. Okamoto N. Kikuchi T. Kato O. Kitakami K. Mitsuzuka T. Shimatsu H. Muraoka H. Aoi J.C. Lodder 《Journal of magnetism and magnetic materials》2008
Bit patterned media (BPM) which utilize each magnetic nanostructured dot as one recorded bit has attracted much interest as a promising candidate for future high-density magnetic recording. In this study, the magnetization reversal behaviors of nanostructured L10-FePt, Co/Pt multilayer (ML), and CoPt/Ru dots are investigated. For Co/Pt and CoPt/Ru nanodots, the bi-stable state is maintained in a very wide size range up to several hundred nm, and the magnetization reversal is dominated by the nucleation of a small reversed nucleus with the dimension of domain wall width. On the other hand, the critical size for the bi-stability of L10-FePt is about 60 nm, and its magnetization reversal proceeds via domain wall displacement even for such a small dot size. These reversal behaviors, depending on the magnetic materials, might be attributed to the difference in structural inhomogeneity, such as defects. In addition to the magnetic properties, the structural uniformity of the material could be crucial for the BPM application. 相似文献
994.
Y. Nakamura M. Nishimura Y. Okamoto H. Osawa H. Aoi H. Muraoka Y. Nakamura 《Journal of magnetism and magnetic materials》2008
In this paper, a low-density parity check (LDPC) coding and iterative decoding system is studied in perpendicular magnetic recording (PMR) with a bit-patterned medium. We propose the efficient iterative decoding algorithm attenuating reliability information, and evaluate the sector error rate (SER) performance of the LDPC coding and iterative decoding system by R/W computer simulations. It is clarified that the proposed systems provide better SER performances than that of the conventional system at an areal density of 1 Tbit/in2 and can also prevent the error floor which appears in the performance of conventional system. 相似文献
995.
H Watanabe Y Ishihara K Okamoto K Oshio T Kanamatsu Y Tsukada 《Journal of magnetic resonance (San Diego, Calif. : 1997)》1998,134(2):214-222
The 3D localized13C spectroscopy methods LINEPT and LODEPT, which are modifications of INEPT and DEPT, are proposed. As long as a13C inversion pulse (180-degree pulse) is applied at 1/(4J) before the proton echo time in LINEPT and a13C excitation pulse (90-degree pulse) is applied at 1/(2J) before the proton echo time in LODEPT, the proton echo time can be set to any value longer than 1/(2J) in LINEPT and longer than 1/Jin LODEPT. As a result, the proton and the13C pulses can be applied separately and these proton pulses can be made slice-selective pulses. These localization features of LINEPT and LODEPT were evaluated using a phantom consisting of a cylinder filled with ethanol placed inside another cylinder filled with oil, and localized ethanol spectra could be obtained.In vivo3D localized13C spectra from the brain of a monkey could be obtained using decoupled LINEPT, and glutamate C-4 appeared directly after the administration of glucose C-1, followed by the appearance of glutamate C-2, C-3 and glutamine C-2, C-3, C-4. 相似文献
996.
A new synthesis of bis-catechol spiroborate and its analogs are described. Not only five-but also six- and seven-membered spiroborates are obtained. The reaction mechanisms are also discussed. 相似文献
997.
Calculations on long-wavelength lattice vibrations have been made for cystallline KNCS within the framework of the rigid ion model. The short range force constants and effective charges of the ions have been determined from the observed frequencies. Unobserved frequencies are predicted, and normal coordinates have been obtained and schematized. 相似文献
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