Crystal Structures Of Intermediate Phases Research Articles

Interaction of Skutterudites with Contact Materials: A Metallurgical Analysis

More than hundred diffusion couples between p- and n-type skutterudites and various materials were prepared and interaction zones were investigated after heat treatment at 600 °C for 1100 h. The constitution of reaction/diffusion zones was discussed in terms of: (a) atom site preference in the skutterudite lattice, (b) phase equilibria in multicomponent systems and (c) particularities of the crystal structure of intermediate phases. It could be shown that phase composition and thermo-mechanical properties of bonding can be engineered by chemical substitution. The results obtained allowed the determination of several necessary criteria for the development of chemically and mechanically stable diffusion barriers/couples for skutterudite based thermoelectric (TE) modules.

ChemInform Abstract: Phase Equilibria and Crystal Structure of the Complex Oxides in the Ln—Ba—Co—O (Ln: Nd, Sm) Systems.

AbstractPhase equilibria in the title systems at 1100 °C in air and the crystal structure of intermediate phases are investigated by powder XRD.

Crystal Structure and Phase Transitions of Intermediate Phase of PbZrO3

Crystal structure of intermediate phase of PbZrO 3 was analyzed by neutron powder diffraction. Superlattice reflections of our sample appeared at M and R points. Intensities of fundamental reflections also changed in the phase. The structural modulations were associated with modes either Γ 15 + M 3 + R 25 or Γ 15 + M ′ 5 + R 25 . The modulation associated with the R 25 mode of our sample might be caused by an extrinsic origin. Dielectric constant was also measured and a mechanism of the phase transitions is discussed briefly.

Crystal Structure of Intermediate Phases in Binary B-Metal Alloys Induced by High Pressure

Crystal Structure of Intermediate Phases in Binary B-Metal Alloys Induced by High Pressure

Intermediate Phases in Some Rare Earth - Rhodium Systems

The phase equilibria and crystal structures of intermediate phases were investigated in eight representative RE-Ru systems using powder X-ray diffraction and metallographic techniques. The Fe3C, Mn5C2 and Er5Ru3 structures occur in all but the Ce-Ru systems. Phases analogous to Er5Ru3 possess an unknown crystal structure similar to Er5Rh3(I). MgCu2 and MgZn2 type Laves phases are encountered in the light rare earth and heavy rare earth systems, respectively, and RERu2 phases, where RE = Nd and Sm, possess both the Laves phase structures. An intermediate phase, NdRu, with an unknown structure, occurs only in the Nd-Ru system. A bcc structure with 40 atoms per unit cell is encountered in the phases Er3Ru2 and Y3Ru2. The behavior of cerium in Ce-Ru alloys is unique in that four unidentified structures, not encountered in other RE-Ru systems, have been encountered. Also a phase designated as Ce3Ru is found with the Th7Fe3 type structure.