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Two CoCrAl alloy samples subjected to different heat treatment regimes are studied. An exact distribution of atoms over the sublattices in the samples is determined by X-ray diffraction and neutron diffraction methods. These data are used to perform ab initio density of states calculations and to calculate the magnetic moments of the samples in a coherent potential approximation. The calculated magnetic moments are compared to the experimental values. The effect of atomic ordering on the electronic structure near the Fermi level is analyzed using optical methods. The possible causes of the detected temperature dependence of the electrical resistivity, unusual for metallic alloys, are discussed. [ABSTRACT FROM AUTHOR]

The structure state of carbon eutectoid steel has been studied by the in situ neutron diffraction method in the temperature range from room temperature to 800°C. It has been shown that an increase in the temperature is accompanied by a decrease in the concentration of carbon in cementite, whereas its weight fraction and the parameters of the orthorhombic lattice change slightly. The ab initio calculations of the nonstoichiometric carbides Fe3C x (0 < x < 1) indicate that the structure of cementite remains stable upon the appearance of vacancies in the carbon sublattice with a relatively low formation energy. Thus, cementite should be considered as an interstitial phase Fe3C x with a wide homogeneity range. [ABSTRACT FROM AUTHOR]

The crystal structure of the low-temperature forms of the Cs3PO4 and Rb3PO4 orthophosphates has been determined for the first time by neutron diffraction using the Rietveld method. Cs3PO4 and Rb3PO4 are shown to be isostructural with K3PO4: orthorhombic cell (sp. gr. Pnma, Z = 4); lattice parameters a = 1.23177(6) nm, b = 0.88948(4) nm, c = 0.64197(3) nm for Cs3PO4; a = 1.17362(2) nm, b = 0.81046(1) nm, c = 0.615167(9) nm for Rb3PO4. [ABSTRACT FROM AUTHOR]

The crystal structure of the low-temperature form of K3PO4 has been determined for the first time using neutron diffraction (Rietveld method) and Raman spectroscopy: orthorhombic cell (sp. gr. Pnma, Z = 4), lattice parameters a = 1.12377(2) nm, b = 0.81046(1) nm, c = 0.59227(1) nm. The structure is made up of isolated [PO4] tetrahedra, with the potassium ions in between. [ABSTRACT FROM AUTHOR]

The crystal structure of the low-temperature form of K3PO4 has been determined for the first time using neutron diffraction (Rietveld method) and Raman spectroscopy: orthorhombic cell (sp. gr. Pnma, Z = 4), lattice parameters a = 1.12377(2) nm, b = 0.81046(1) nm, c = 0.59227(1) nm. The structure is made up of isolated [PO4] tetrahedra, with the potassium ions in between. [ABSTRACT FROM AUTHOR]