The systems Sr-Zn-{l_brace}Si,Ge{r_brace}: Phase equilibria and crystal structure of ternary phases

Journal Article · Wed Feb 15 04:00:00 EST 2012 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.11.037· OSTI ID:21612895

Romaka, V V; Falmbigl, M; Grytsiv, A ^[1]; Rogl, P ^[1]

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1. Institute of Physical Chemistry, University of Vienna, Waehringerstr. 42, A-1090 Wien (Austria)

Phase relations have been established by electron probe microanalysis (EPMA) and X-ray powder diffraction (XPD) for the Sr-poor part of the ternary systems Sr-Zn-Si at 800 Degree-Sign C and Sr-Zn-Ge at 700 Degree-Sign C. In the Sr-Zn-Si system one new ternary compound SrZn{sub 2+x}Si{sub 2-x} (0{<=}x{<=}0.45) with CeAl{sub 2}Ga{sub 2} structure and a statistical mixture of Zn/Si in the 4e site was found. Neither a type-I nor a type-IX clathrate phase was encountered. This system is characterized by formation of two further phases, i.e. SrZn{sub 1-x}Si{sub 1+x} with ZrBeSi-type (0.16{<=}x{<=}0.22) and SrZn{sub 1-x}Si{sub 1+x} with AlB{sub 2}-type (0.35{<=}x{<=}0.65) with a random distribution of Zn/Si atoms in the 2c site. For the Sr-Zn-Ge system, the homogeneity regions of the isotypic phases SrZn{sub 1-x}Ge{sub 1+x} with ZrBeSi-type (0{<=}x{<=}0.17) and AlB{sub 2}-type (0.32{<=}x{<=}0.56), respectively, have been determined. Whereas the germanide SrZn{sub 2+x}Ge{sub 2-x} (CeAl{sub 2}Ga{sub 2}-type) is characterized by a homogeneity region (0{<=}x{<=}0.5), the clathrate type-I phase Sr{sub 8}Zn{sub 8}Ge{sub 38} shows a point composition. - Graphical abstract: Phase equilibria of ternary compounds in the Sr-Zn-Si-system at 800 Degree-Sign C. Highlights: Black-Right-Pointing-Pointer Phase equilibria in the Sr-Zn-Si-system are established at 800 Degree-Sign C. Black-Right-Pointing-Pointer Phase equilibria in the Sr-Zn-Ge-system are established at 700 Degree-Sign C. Black-Right-Pointing-Pointer Crystal structures of the ternary compounds were confirmed by X-ray powder diffraction. Black-Right-Pointing-Pointer All ternary compounds except the clathrate-I in the Ge-system are characterized by a homogeneity region.

• OSTI ID: 21612895
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. 186; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CHEMICAL ANALYSIS
CLATHRATES
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON MICROPROBE ANALYSIS
ELECTRON SPECTROSCOPY
GERMANIDES
GERMANIUM COMPOUNDS
MICROANALYSIS
NONDESTRUCTIVE ANALYSIS
PHOTOELECTRON SPECTROSCOPY
SCATTERING
SILICIDES
SILICON COMPOUNDS
SPECTROSCOPY
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY