Intermetallic compounds having compositions from HfCo4 to HfCo8 were investigated by transmission electron microscopy, selected-area electron diffraction, and energy-dispersive x-ray spectroscopy. A major crystalline phase, closely related to the orthorhombic Zr2Co11 phase in structure, has been observed in the samples with the composition ranges from HfCo6 to HfCo8. The phase, referred to as e...

The structure and elastic properties of MgSiOa, a major mantle-forming phase, have been simulated using computer models which predict the minimum energy structure by using interatomic pair potentials to describe the net forces acting between the atoms. Four such interatomic potentials were developed in this study, and are compared with potential NI of Miyamoto and Takeda (1984). The most succes...

Solid-state (17)O NMR spectroscopy is employed to characterize powdered samples of known monoclinic and orthorhombic modifications of (17)O-enriched triphenylphosphine oxide, Ph(3)PO. Precise data on the orientation-dependent (17)O electric field gradient (EFG) and chemical shift (CS) tensors are obtained for both polymorphs. While the (17)O nuclear quadrupolar coupling constants (C(Q)) are ess...

A lattice metric singularity occurs when unit cells defining two (or more) lattices yield the identical set of unique calculated d-spacings. The minerals Mawsonite and Chatkalite are of especial interest as both are characterized by tetragonal unit cells that correspond to the second member of a quaternary lattice metric singularity. This singularity includes lattices that are Cubic I, Tetragon...

Sr6Nb10O30–Nb2O5 nanocomposite was synthesized in 2M NaOH aqueous solution. A stoichiometric 1:1 Sr:Nb molar ratio hydrothermal method at 120°C was used to synthesize this nanocomposite. Sr(NO3)2 and Nb2O5 were used as raw materials. The synthesized nanomaterials were characterized by powder X-ray diffraction (PXRD) technique. It was found that Sr6Nb10O30 was crystallized in tetragonal crystal ...

We investigate high-pressure induced phase transitions of YF3 and Eu-doped YF3 (YF3:Eu(3+)) by using the angular dispersive synchrotron X-ray diffraction technique at room temperature. It is found that the starting orthorhombic phase transforms into a new high-pressure phase which is identified as hexagonal structure in both YF3 and YF3:Eu(3+). The high-pressure structure of YF3 and YF3:Eu(3+) ...

Ferromagnetism and its evolution in the orthorhombic perovskite system Sr(1-x)Ca(x)RuO3 have been widely believed to correlate with structural distortion. The recent development of high-pressure synthesis of the Ba-substituted Sr(1-y)Ba(y)RuO3 makes it possible to study ferromagnetism over a broader phase diagram, which includes the orthorhombic Imma and the cubic phases. However, the chemical ...