Kozo Nagashima

The crystal structure of a new synthetic sulfosalt, KHgSbS3

A new sulfosalt, KHgSbS3 is orange in color with tabular shape and crystallizes in the monoclinic space group A2a with a=17.084(8), b=8.647(4), c=8.951(3) A, β=105.78(5)°, and z=8. The crystals are obtained as twin, which is related by a 180° rotation of the reciprocal lattice around [100] with (100) twin plane. The structure was determined by three dimensional Patterson synthesis and refined to a final R-value of 0.082 for 737 reflections. The crystal structure consists of trigonal pyramids of SbS3 linked together by Hg atoms to form a two dimensional sheet-like network. The K atoms are located between the sheets, bonded weakly to them.

Preparation and characterization of the new quaternary chalcogenides Tl-III-IV-S4 (III = Al, Ga, In; IV = Si, Ge)

Five new chalcogenides: T1InSiS/sub 4/, T1InGeS/sub 4/, T1GaSiS/sub 4/, T1GaGeS/sub 4/, T1A1GeS/sub 4/ were synthesized by the evacuated silica tube method. The crystals are isotypic and belong to the orthorhombic system with space group Pbnm and lattice parameters in the range of, a: 11.53 -11.74, b: 16.50-17.04, c: 7.036-7.353 A. Infrared and photoacoustic spectra of these compounds are also reported.

Phase diagram and valence state of iron in FeNb2O6 synthesized under controlled redox atmosphere

FeNb2O6 crystals were synthesized by melt/sintering method under controlled gas flow of CO2/H2. Phase of the crystals obtained was different depending on the partial oxygen pressure (PO2). At high partial oxygen pressures, columbite type structure was formed and the valence state of iron was found to be both ferrous and ferric. At low partial oxygen pressures, trirutile type structure was formed and the valence state of iron was found to be ferrous. At intermediate partial oxygen pressures, both the columbite type and the trirutile type structures were found in the products.

A new absorption correction based on a normalized lonization distribution model for electron microprobe analysis and its application for oxygen analysis

SummaryThis paper described a new absorption correction for electron microprobe analysis and its application for oxygen analysis in inorganic compounds. The proposed absorption correction was described as

The Measurement of Relative Isotope Abundance Ratios by Nuclear Magnetic Resonance Techniques

f(\chi ) = A[exp(v^2 )erfc(v) - B[exp(u^2 )erfc(u)],

sup 207

whereA=[exp(c2)(1+erf(c))−B)]−1,B=6.65×10−2,

Quantitative microprobe analysis of hydrous minerals using OKα line. Estimation of water content in microarea

u = \chi \cdot \overline {\varrho z} /6.64,v = \chi \cdot \overline {\varrho z} /1.33 - c