P.S. Salamakha

CeNiGe and NdNiGe phase diagrams: systematics of rare earth-nickel-germanium compounds

Abstract The ternary systems Ce(Nd)NiGe have been investigated and phase relations have been determined at 870 K, where respectively 20 and nine compounds were observed. A critical assessment on the interaction of rare earth elements with nickel and germanium has been made.

Dy117Co57Sn112, a new structure type of ternary intermetallic stannides with a giant unit cell

Abstract The crystal structure of a new ternary stannide Dy 117 Co 57 Sn 112 , space group Fm-3m (N225), a =29.831(4) A, Z =4, V =26546.26(1) A 3 , μ =40.34 mm −1 was refined from single-crystal X-ray diffraction data to R =0.0689, R w2=0.1119 from 1000 reflections hkl with I >4 σ ( I ) and 89 variable parameters. The structure is related to the Tb 117 Fe 52 Ge 112 structure type and contains 1144 atoms per unit cell.

CeFeGe, NdFeGe and HoFeGe phase diagrams: systematics of rare earth-iron-germanium compounds

Abstract The ternary systems Ce(Nd,Ho)FeGe have been investigated and phase relations have been determined at 870 K, where respectively seven, eight and six compounds were observed. A critical assessment on the interaction of rare earth elements with iron and germanium has been made.

Interaction behaviour of neodymium and silver with elements of Group IVa at 600°C

Abstract Phase equilibria have been established in the ternary NdAgGe(Sn) systems over the whole concentration region and in the ternary NdAgPb system within 0–33 at.% Nd for an isothermal section at 600°C. Seven ternary intermetallic compounds of silver and neodymium have been observed: NdAg 2 Ge 2 , Nd 2 AgGe 6 , NdAg 1.1 Ge 0.9 , Nd 6 Ag 8 (Ge)Sn 8 and NdAgSn(Pb).

The phase equilibria in the quasi-ternary Ag2SeGa2Se3GeSe2 system

Abstract The seven polythermal sections of the quasi-ternary HgSeGa 2 Se 3 GeSe 2 system were investigated using differential thermal, X-ray phase and microstructural analyses and microhardness measurement. New quaternary compounds were not found. Extended solid solutions on the basis of Ga 2 Se 3 and HgSe have been established. The projection of the liquidus surface and the isothermal section of the HgSeGa 2 Se 3 GeSe 2 phase diagram at 770 K over the whole concentration region have been constructed.

Crystal structure of ternary CeRhX compounds, X=As, Sb, Bi

Abstract Three intermetallic compounds CeRhAs, CeRhSb and CeRhBi were structurally studied by X-ray powder diffraction. From Rietveld refinement, all of them were found to crystallize in the TiNiSi structure type, space group Pnma (N62), a =0.75351(9) nm, b =0.43081(6) nm, c =0.73653(9) nm for CeRhAs, a =0.74150(3) nm, b =0.46185(2) nm, c =0.78570(3) nm for CeRhSb and a =0.74648(5) nm, b =0.47173(4) nm, c =0.79715(6) nm for CeRhBi. Refined atomic positional and thermal parameters are presented.

57Fe Mössbauer spectroscopy study of the AFexAl12−x intermetallics (AY, Tm, Lu and U, 4≤x≤4.3)

Abstract AFe x Al 12− x intermetallics (AY, Tm, Lu and U, 4≤ x ≤4.3) were synthesized as polycrystalline material and as large single crystals by the Czochralski method from bulk charges containing A, Fe and Al in the atomic ratios 1/4/8. The purity of the studied samples was checked by powder X-ray diffraction and their final composition was estimated using the Rietveld method of structure refinement. The 57 Fe Mossbauer spectra of samples with final composition x >4 have revealed that the Fe atoms on the same crystallographic site may have different magnetic moments, μ Fe , whose values increase with the number of Fe nearest neighbours. The strong sensitivity of the μ Fe on small deviations from the ideal 1/4/8 stoichiometry has clearly shown that while the single crystals of UFe 4 Al 8 grown by the Czochralski method have the expected composition, those grown from YFe 4 Al 8 and LuFe 4 Al 8 bulk charges have actual compositions YFe 4.2(1) Al 7.8(1) and LuFe 4.2(1) Al 7.8(1) thus explaining contradictory results that have been previously published.

The neodymium-(vanadium, chromium, manganese)-silicon systems

Abstract The isothermal sections of the Nd{V,Cr,Mn}Si phase diagrams at 870 K over the whole concentration region have been constructed using X-ray phase analysis. Ternary compounds are not formed in the NdVSi system. We have confirmed the existence of the previously reported ternary compounds NdMn 2 Si 2 with the CeGa 2 Al 2 -type structure, and NdMnSi with the PbFCl-type structure. A new ternary compound, i.e. NdCr 2 Si 2 , with the CeGa 2 Al 2 -type structure has been prepared for the first time and its crystal structure has been determined using X-ray powder diffraction data. The limits of solid solution of the binary compound NdSi 1.8 have been established.

Y–Fe–Al ternary system: partial isothermal section at 1070 K: Powder X-ray diffraction and Mössbauer spectroscopy study

Abstract Phase equilibria were established in the Y–Fe–Al ternary system within the concentration region 50–100 at.% Al for an isothermal section at 1070 K by means of scanning electron microscopy and powder X-ray diffraction. Two ternary aluminides were observed, YFe x Al 12− x (4≤ x ≤5.6) with the ThMn 12 -type structure, a =8.6467(9)–8.7604(7) A, c =5.0374(6)–5.0504(5) A and YFe 2 Al 10 , YbFe 2 Al 10 -type structure, a =8.9649(6) A, b =10.1568(6) A, c =9.0113(6) A. The only binary which forms a prolonged solid solution range is YAl 2 . The unit cell edge of the YFe x Al 2− x compounds, MgCu 2 -type structure, decreases with Fe content from 7.834(9) A for x =0 down to 7.689(4) A for x =0.5. 57 Fe Mossbauer spectroscopy data of YFe 2 Al 10 show an unusually large isomer shift for Fe in Al-containing intermetallics and confirm that no magnetic ordering occurs down to 5 K.

The neodymium–zinc–(silicon, germanium) systems

Abstract The isothermal sections of the Nd–Zn–(Si,Ge) phase diagrams at 870 K over the whole concentration region have been constructed using X-ray phase analysis. The formation of the previously reported phase NdZn1.5Ge0.5 (AlB2 structure type) was confirmed, and eight new ternary compounds were observed. The crystal structures of the NdZnSi (AlB2 structure type) and NdZn0.5−xSi1.5+x (x=0.2, α-ThSi2 structure type) compounds were determined using X-ray powder diffraction data.