Lattice Spacings in Some Transition Metal Terminal Solid Solutions

1962 ◽  
Vol 6 ◽  
pp. 121-135 ◽  
Author(s):  
Henry Chessin ◽  
Sigurds Arajs ◽  
D. S. Miller
Keyword(s):  
Transition Metal ◽  
Size Effect ◽  
Elasticity Theory ◽  
Solid Solutions ◽  
Calculated Data ◽  
Lattice Parameter ◽  
Lattice Parameters ◽  
Classical Elasticity ◽  
Atomic Size ◽  
Classical Elasticity Theory

AbstractThe lattice parameter-composition curves for several nickel solid solutions and for some chromium and. iron solid solutions are discussed. It is shown that the size effect may be the predominating influence on the change of lattice parameters in these systems. This is demonstrated by comparing observed and calculated data employing various methods. A new scheme for evaluating the atomic size in solid solutions is proposed, based on regarding the atom, as an incompressible core surrounded by a smeared-out compressible volume. The suggestion that classical elasticity theory may be used as a basis for understanding the size effect in solid solutions is justified by examination of the Ag-Pd system for additions of Ag from 0 to 100 at. %.

LATTICE PARAMETERS OF MELILITE SOLID SOLUTIONS AND A RECONNAISSANCE OF PHASE RELATIONS IN THE SYSTEM Ca2Al2SiO7 (GEHLENITE) – Ca2MgSi2O7 (AKERMANITE) – NaCaAlSi2O7 (SODA MELILITE) AT 1 000 kg/cm2 WATER VAPOR PRESSURE

1965 ◽  
Vol 2 (6) ◽  
pp. 596-621 ◽  
Author(s):  
A. D. Edgar
Keyword(s):  
Solid Solutions ◽  
Water Vapor Pressure ◽  
Lattice Parameter ◽  
Lattice Parameters ◽  
Phase Relations ◽  
Ray Method ◽  
Subsolidus Phase ◽  
X Ray ◽  
Complete Solid Solution ◽  
Temperature Lattice

The extent of melilite solid solutions has been determined for the systems gehlenite–soda melilite, akermanite–soda melilite, and gehlenite–akermanite–soda melilite at 800 °C and 1 000 kg/cm2[Formula: see text] Approximately 50 weight % NaCaAlSi2O7 will form melilite solid solutions with both gehlenite and akermanite but the extent of complete solid solutions in the gehlenite–akermanite–soda melilite system is very limited at this temperature. Lattice parameter determinations of melilite solid solutions indicate that there is a small but significant change in both a and c parameters with increasing soda melilite in the gehlenite–soda melilite system. In the gehlenite–akermanite–soda melilite system, although the range of complete solid solution is very limited, melilites form more than 90% of the products in most compositions and their lattice parameters can be correlated approximately with their bulk compositions, A rapid X-ray method has been developed to determine the approximate compositions of melilites in this system. Comparison is made between the synthetic samples and natural melilites.A reconnaissance of subsolidus phase relations indicates that phase relations are very complex and that only over a very small compositional range can these systems be considered binary or ternary. These studies also indicate that the relations reported by Nurse and Midgley in 1953 should probably be modified. Although the composition NaCaAlSi2O7 does not synthesize only a melilite under the conditions used in this study, it is believed that this is the correct composition of the sodium-bearing end-member.

Elasticity Theory for Indentation of a Rubber Plate

1968 ◽  
Vol 41 (5) ◽  
pp. 1122-1131 ◽  
Author(s):  
S. D. Gehman
Keyword(s):  
Elasticity Theory ◽  
Thickness Dependence ◽  
Classical Elasticity ◽  
Rubber Specimen ◽  
Empirical Correction ◽  
Classical Elasticity Theory ◽  
Rubber Plate

Abstract Rubber hardness readings with an indenter depend upon thickness of the rubber specimen. This effect has been known and studied since first attempts to develop precision methods to determine hardness. Classical elasticity theory accounted satisfactorily for indentation relations with thick rubber but thickness dependence was treated as an empirical correction.

Au3SnCuP10 and Au3SnP7: Preparation and Crystal Structures of Au3Sn Heterocluster Polyphosphides

2006 ◽  
Vol 61 (7) ◽  
pp. 871-881 ◽  
Author(s):  
Stefan Lange ◽  
Tom Nilges
Keyword(s):  
Transition Metal ◽  
Crystal Structures ◽  
Homologous Series ◽  
Structure Refinement ◽  
Chair Conformation ◽  
Lattice Parameter ◽  
Lattice Parameters ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Tetrahedral Voids

The formation of Au3Sn heteroclusters completes the homologous series of M3Sn clusters observed for transition metal main-group polyphosphides. Au3SnCuP10 is cubic, space group F4̅3̅m (No. 216) with lattice parameter a = 10.3953(5) Å . The structure refinement yielded R1 = 0.0353 and wR2 = 0.0726 for 154 F2 values and 13 variables. Disordered Au3Sn heteroclusters occupy all octahedral, and adamantane like P10 cages one half of the tetrahedral voids of a face-centred cubic ( fcc) arrangement of copper. Ordered and orientationally disordered Au3Sn heteroclusters have been observed for Au3SnP7, embedded in a 1∞ [P7] polyphosphide unit formed by six-membered phosphorus rings in chair conformation which are linked by a P-bridge. Au3SnP7 is monoclinic, space group P21/m (No. 11) with lattice parameters of a = 6.219(2), b = 10.836(2), c = 6.318(2) Å , β = 108.65(2)°, V = 403.4(2) Å3, R1 = 0.0412 and wR2 = 0.0745, 1261 F2 values and 56 variables. Au3SnP7 with disordered Au3Sn clusters has slightly larger lattice parameters of a = 6.343(3), b = 10.955(3), c = 6.372(3) Å , β = 108.63(2)°, V = 419.6(2) Å3, R1 = 0.0324 and wR2 = 0.0691, 1131 F2 values and 58 variables.

Stiffness characteristics of rubber impact absorbers

1972 ◽  
Vol 7 (1) ◽  
pp. 33-40 ◽  
Author(s):  
E A Bakirzis
Keyword(s):  
Elasticity Theory ◽  
Classical Elasticity ◽  
Cross Sectional ◽  
Wide Range ◽  
Stiffness Characteristics ◽  
Classical Elasticity Theory

Classical elasticity theory, together with a knowledge of the behaviour of solid-rubber pads under compression, is employed to predict the force-deflection characteristics of hollow rubber units used as impact absorbers. Various parameters are predicted theoretically and agreement with theory is found to be satisfactory for a wide range of shapes and ratios of cross-sectional dimensions.

scholarly journals Cerium oxide based nanometric powders: synthesis and characterization

2007 ◽  
Vol 39 (3) ◽  
pp. 301-308 ◽  
Author(s):  
M. Ninic ◽  
S. Boskovic ◽  
M. Nenadovic ◽  
S. Zec ◽  
K. Voisavljevic ◽  
...  
Keyword(s):  
Rare Earth ◽  
Cerium Oxide ◽  
Solid Solutions ◽  
Oxygen Vacancies ◽  
Total Concentration ◽  
Lattice Parameter ◽  
Lattice Parameters ◽  
Synthesis And Characterization ◽  
In Doping ◽  
Host Compound

Nanometric powders of solid solutions of cerium oxide were obtained by a modified glycine nitrate procedure. Solid solutions of the host compound CeO2 with one or more dopants in the lattice were synthesized. Rare earth cations (Re=Yb, Gd and Sm) were added to ceria in total concentration of x= 0.2 that was kept constant. The criterion in doping was to keep the value of lattice parameter of ceria unchanged. The lattice parameters were calculated by using the model that takes into account the existence of oxygen vacancies in the structure.

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