1,151 research outputs found
59Co-NMR Knight Shift of the Superconducting NaxCoO2.yH2O
Layered Co oxide NaxCoO2.yH2O with the superconducting transition temperature
Tc =4.5 K has been studied by 59Co-NMR. The Knight shift K estimated from the
observed spectra for powder sample exhibits almost temperature(T)-independent
behavior above Tc and decreases with decreasing T below Tc. This result and the
existence of the coherence peak in the spin-lattice-relaxation-rate versus T
curve reported by the present authors indicate, naively speaking, that the
singlet order parameter with s-wave symmetry is realized in NaxCoO2.yH2O.
Differences of the observed behaviors between the spectra of the non-aligned
sample and the one aligned in epoxy adhesive by applying the external magnetic
field are discussed.Comment: 6 pages, 4 figures, submitted to J. Phys. Soc. Jp
Critical Behavior in Doping-Driven MetalInsulator Transition on Single-Crystalline Organic Mott-FET
We present the carrier transport properties in the vicinity of a
doping-driven Mott transition observed at a field-effect transistor (FET)
channel using a single crystal of the typical two-dimensional organic Mott
insulator -(BEDT-TTF)CuN(CN)Cl (-Cl).The FET shows a
continuous metalinsulator transition (MIT) as electrostatic doping proceeds.
The phase transition appears to involve two-step crossovers, one in Hall
measurement and the other in conductivity measurement. The crossover in
conductivity occurs around the conductance quantum , and hence is not
associated with "bad metal" behavior, which is in stark contrast to the MIT in
half-filled organic Mott insulators or that in doped inorganic Mott insulators.
Through in-depth scaling analysis of the conductivity, it is found that the
above carrier transport properties in the vicinity of the MIT can be described
by a high-temperature Mott quantum critical crossover, which is theoretically
argued to be a ubiquitous feature of various types of Mott transitions. [This
document is the unedited Authors' version of a Submitted Work that was
subsequently accepted for publication in Nano Letters, copyright \copyright
American Chemical Society after peer review. To access the final edited and
published work see http://dx.doi.org/10.1021/acs.nanolett.6b03817]Comment: 40 pages, 16 figures in Nano Letters, ASAP (2017
Lip incompetence and myofunctional therapy
Lip incompetence, which is a state in which the upper and lower lips are constantly apart, is thought to induce mouth breathing that may result in the development of gingivitis and periodontal disease. In the orthodontic field, lip incompetence has major problems for diagnosis, when determining the treatment goal and at the time of retention. We have been performing studies on lip incompetence and have obtained the following results : (1) it is possible to predict to some extent the state of lip closure during sleep by examination only in an awake state, (2) anterior teeth are positioned forward in individuals with lip incompetence, and (3) a training method called Button Pull is effective as a myofunctional therapy for improving lip incompetence, but there remains a need to clarify the background
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