Biomedical subjects

Akira Yoshiasa

Publications and source records attributed to Akira Yoshiasa.

3 recordsLinked to original sources

PubMed2004

Oxygen-deficient strontium cobaltate, SrCoO2.64.

Single crystals of strontium cobaltate, SrCoO(3-x), have been grown by the floating-zone method in an oxygen flow. The compound crystallizes with the cubic perovskite structure, with Pm-3m symmetry, as determined by X-ray diffraction. Refinement of the O-atom site occupancy yields the chemical composition SrCoO(2.64) [x = 0.36 (3)]. The anisotropic displacement ellipsoids of the O atoms suggest that their positional disorder occurs in a direction perpendicular to that of the Co-O bonds.

Journal Article↗

PubMed2004

Pressure-induced sharp coordination change in liquid germanate.

Local structures around germanium in liquid germanate have been investigated by means of in situ x-ray absorption measurements up to 9 GPa at 1273 K. Liquid germanate consisting of tetrahedrally coordinated germanium contracts with increasing pressure without significant changes in the local structure up to 2.5 GPa and then shows an abrupt fourfold-to-sixfold coordination change around 3 GPa. The coordination change is completed below 4 GPa where upon a high-density liquid consisting of octahedrally coordinated germanium becomes stable. The GeO6 octahedron in the high-density liquid is more compressible than that in solids.

Journal Article↗

PubMed2003

Vanadate garnet, Ca2NaMg2V3O12.

The vanadate garnet Ca(2)NaMg(2)V(3)O(12) (dicalcium sodium dimagnesium trivanadium dodecaoxide), synthesized by a floating zone method, has a notable structural feature in that the dodecahedral-dodecahedral shared edge length is longer than the unshared dodecahedral edge length. It is also noteworthy that the octahedral-dodecahedral shared edge length is as long as the unshared octahedral edge length. These unusual structural features are closely related to the weak repulsions between dodecahedral cations and between dodecahedral and octahedral cations.

Journal Article↗