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A computed tomography (CT) imaging system using monochromatic sub-terahertz coherent electromagnetic waves generated from a device constructed from the intrinsic Josephson junctions in a single crystalline mesa structure of the high-Tc superconductor Bi2Sr2CaCu2O8+δ was developed and tested on three samples: Standing metallic rods supported by styrofoam, a dried plant (heart pea) containing seeds, and a plastic doll inside an egg shell. The images obtained strongly suggest that this CT imaging system may be useful for a variety of practical applications. [ABSTRACT FROM AUTHOR]

TLPS (Transient Liquid Phase Sintering) process is a candidate method for heat-resistant bonding, which makes use of the reaction between low-melting temperature powder of Sn-Bi base alloys and reactive powder of Ag. During heat treatment above the melting temperature of a Sn-Bi base alloy, the molten Sn-Bi reacts rapidly with solid Ag particles, which results in the formation of a heat-resistant intermetallic compound (IMC). In this study, the TLPS properties between Sn-17Bi-1Ag (at.%) powder with a liquidus temperature of 200°C and pure Ag powder were investigated. During differential scanning calorimetry (DSC) measurement, an exothermic reaction and an endothermic reaction occurred, which correspond to the formation of the ε-Ag3Sn-IMC phase and the melting of the Sn-17Bi-1Ag alloy, respectively. After the overall measurement, the obtained reactant consisted of the Ag3Sn-IMC and Bi-rich phases, both of which started melting above 250°C, with a small amount of the residual Sn-Bi eutectic phase. These results suggest that the TLPS process can be applied for Pb-free heat-resistant bonding. [ABSTRACT FROM AUTHOR]

The general formula of the amphiboles of this series may be written as NaxMg2(Mg(5–y)Aly)(Si(8–z)Alz)O22(OH)2, where Mg = Mg + Fe2+ + Mn2+ and Al = Al + Fe3+ + Ti. The individual distances are linear functions of their [4]Al content, and the [4]Al content is strongly ordered in the following way: T1B > T1A ≫ T2B ≫ T2A. The , and distances are linear functions of the mean ionic radius of their constituent cations. End-member compositions may be written as follows: A□Mg2Mg5Si8O22(OH)2; ANaMg2Mg5(Si7Al)O22(OH)2; A□Mg2(Mg3Al2)(Si6Al2)O22(OH)2; ANaMg2(Mg3Al2)(Si5Al3)O22(OH)2. These compositions define a plane in xyz space across which the data of Schindler et al. (2008), measured on amphiboles fromam phibolites, follow a tightly constrained trajectory. Anthophyllite–gedrite amphiboles equilibrated under significantly different P-T conditions (e.g. igneous rocks, contact-metamorphic rocks) follow trends that diverge fromthis trajectory, with greater Na and [4]Al contents and relatively smaller [6]Al contents. Detailed examination of the local bond topology involving the A and M2 sites indicates that the maximum degree of bond-valence compensation will occur for incorporation of ANa and M2Al in the ratio 4:10, and hence 2.5 ANa = M2Al in these amphiboles. This relation closely fits the data of Schindler et al. (2008), suggesting that the variation in chemical composition in anthophyllite–gedrite amphiboles is strongly constrained by the anion bond-valence requirements of the Pnma amphibole structure. We further suggest that different compositional trends for orthoamphiboles equilibrated under different P-T conditions are the result of the valence-sumrule operating with (different) bond-lengths characteristic of these P-T conditions. [ABSTRACT FROM AUTHOR]

The crystal structures of twenty-five orthorhombic Fe-Mg-Mn amphiboles, a = 18.525–18.620, b = 17.806–18.034, c = 5.264–5.303 Å, V = 1737.6–1776.7, space group = Pnma, Z = 4, have been refined to R indices in the range 2.1–7.8% using 790–1804 unique observed reflections measured with Mo-Kα X-radiation on a Bruker P4 automated four-circle diffractometer equipped with a 1K CCD detector. The quality of the refinements is strongly a function of the [4]Al content of the crystals because of unmixing in the central part of the series due to the presence of a low-temperature solvus. The amphibole crystals were analysed by electron microprobe subsequent to collection of the X-ray intensity data and span the anthophyllite–gedrite series from 0.17–1.82 [4]Al a.p.f.u. Mössbauer spectroscopy shows that the amphiboles of this series commonly contain small but significant amounts of Fe3+. The amount of [4]Al is linearly related to the grand distance by the equation = 1.6214 + 0.171 [4]Al, R = 0.980; the slope of this relation is not significantly different fromthat characteristic of a hard-sphere model. The distances indicate the following site preference for [4]Al: T1B > T2B > T1A ≫ T2A. The distances are compatible with all [6]Al and Fe3+ ordered at the M2 site. The grand distance is related to the mean radius of the constituent cations, , by the equation ≪M1,2,3−O≫ = 1.4684 + 0.8553(7) . [ABSTRACT FROM AUTHOR]

The principal infrared OH-stretching bands in the orthorhombic (Mg, Fe, Mn, Li) amphiboles holmquistite and anthophyllite show fine structure due to the occurrence of two symmetrically distinct OH groups in the crystal structure. There are two distinct tetrahedral double chains in the orthorhombic amphibole structure, the A chain and the B chain. The B chain is more rotated than the A chain, and the stereochemistry around each of the OH sites suggests that the hydrogen bond to the bridging anion(s) of the B chain is stronger than the hydrogen bond to the bridging anion(s) of the A chain. This difference is sufficient to shift the frequency of the principal OH2-stretching band(s) ~5 cm -1 to lower frequency, and allows resolution of the two bands in the infrared spectrum. This distinction could allow detection of possible OH, F ordering between the two distinct monovalent-anion sites in the orthorhombic amphibole structure. [ABSTRACT FROM AUTHOR]

Abstract Magnetic properties on Sr2-xCaxRuO4 have been investigated by a microscopic probe of 87Sr-NMR in order to understand the magnetic character on spin-triplet superconductor of Sr2RuO4, which has multibands on the Fermi surface. With substituting Ca for Sr which gives rise to crystal distortion, the Knight shift (K) and the nuclear spin-lattice relaxation rate divided by temperature (1/T1T) increases progressively up to x=1.5. The Korringa relation from K and 1/T1T becomes smaller, indicative of development of ferromagnetic fluctuations with increasing Ca content. This suggests that the q-independent spin fluctuations originating from the 2-dimensional ? band are changed to the ferromagnetic ones by the Ca doping. [ABSTRACT FROM AUTHOR]

In order to understand the electronic origin of the inverse magnetocaloric effect observed in a Ni-Co-Mn-In system we used a combination of indirect experimental probes as magnetization, resistivity and specific heat. The findings are compared with the band structure of isostructural Heusler alloys such as Ni-Mn-Ga. We suggest that the inverse magnetocaloric effect in Ni-Co-Mn-In originates from the high density of states close to Fermi energy. Within the austenite state this causes ferromagnetic band splitting. The structural change to the martensite allows an alternative way to reduce the high density of states at lower temperatures, which does not require band splitting and thus does not support ferromagnetic order. [ABSTRACT FROM AUTHOR]