Thermal expansion of silicate perovskite and stratification of the Earth's mantle

Nature ◽  
1986 ◽  
Vol 319 (6050) ◽  
pp. 214-216 ◽  
Author(s):  
Elise Knittle ◽  
Raymond Jeanloz ◽  
Gordon L. Smith
Keyword(s):  
Thermal Expansion ◽  
Earth’S Mantle

The effect of non-stoichiometry on the high-temperature behaviour of MgAl2O4 spinel

2009 ◽  
Vol 73 (2) ◽  
pp. 301-306 ◽  
Author(s):  
F. Nestola ◽  
L. Secco ◽  
M. Bruno ◽  
M. Prencipe ◽  
F. Martignago ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Spinel Structure ◽  
X Ray Diffraction ◽  
Temperature Behaviour ◽  
Mgal2o4 Spinel ◽  
X Ray ◽  
Cation Vacancies ◽  
Earth’S Mantle ◽  
Polyhedral Volumes

AbstractThe effect of cation vacancies upon the thermal expansion and crystal structure of a synthetic defect spinel with composition Mg0.4Al2.4☐0.2O4 was investigated by X-ray diffraction, in situ, at temperatures up to 1273 K. No evidence of symmetry violations from the Fd3m evenat the highest temperature were noted. The volume thermal expansion is markedly less than that of stoichiometric MgAl2O4 spinel, regardless of the degree of inversion. The u oxygen atomic coordinate remains constant throughout the temperature range investigated, with the M–O an dT–O bond lengths showing identical rates of expansivities. An analysis of the evolution of polyhedral volumes with temperature indicates that at 1273 K the octahedron inflates by 0.099 Å3 and the tetrahedron by 0.056 Å3. The expansion of the octahedron is significantly greater than in stoichiometric MgAl2O4 spinel, whereas the expansion of the tetrahedron is similar. The results demonstrate that an excess of Al in the spinel structure accompanied by the formation of cation vacancies strongly affect an important thermodynamic property, in this case, thermal expansion. Such an effect must be considered for those phases stable inthe Earth’s mantle where 4–5 wt.% Al2O3 is thought to be present.

Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

1991 ◽  
Vol 49 ◽  
pp. 962-963
Author(s):  
J. Cooper ◽  
O. Popoola ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Glass Matrix ◽  
Nickel Sulfide ◽  
Plate Glass ◽  
Thermal Expansion Mismatch ◽  
Volume Increase ◽  
Β Phase ◽  
Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

Melt mapped inside Earth’s mantle

Nature ◽  
2020 ◽  
Vol 586 (7830) ◽  
pp. 506-507
Author(s):  
Laura Cobden
Keyword(s):  
Earth’S Mantle

Thermal Expansion of Martensitic A15 Superconductors: V3Si

1995 ◽  
Vol 05 (C8) ◽  
pp. C8-1109-C8-1113
Author(s):  
T.R. Finlayson, ◽  
M. Liu ◽  
T.F. Smith
Keyword(s):  
Thermal Expansion

STRUCTURAL TRANSFORMATION STUDIED BY THERMAL EXPANSION ON SINGLE CRYSTALS V3Si IN NORMAL AND SUPERCONDUCTING STATES

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-406-C6-407 ◽  
Author(s):  
T. Fukase ◽  
T. Kobayashi ◽  
M. Isino ◽  
N. Toyota ◽  
Y. Muto
Keyword(s):  
Thermal Expansion ◽  
Single Crystals ◽  
Structural Transformation

FREE VOLUME CHANGE OF METALLIC GLASSES STUDIED BY THERMAL EXPANSION MEASUREMENTS

1980 ◽  
Vol 41 (C8) ◽  
pp. C8-875-C8-877
Author(s):  
E. Girt ◽  
P. Tomić ◽  
A. Kuršumović ◽  
T. Mihać-Kosanović
Keyword(s):  
Thermal Expansion ◽  
Free Volume ◽  
Volume Change ◽  
Metallic Glasses

MAGNETIC, THERMAL EXPANSION, AND ELECTRICAL RESISTIVITY STUDIES OF FeAlMnC STEELS

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-1903-C8-1904
Author(s):  
S. U. Jen ◽  
Y. D. Yao ◽  
H. Y. Pai
Keyword(s):  
Electrical Resistivity ◽  
Thermal Expansion

THERMAL EXPANSION ANOMALIES AT THE MAGNETIC TRANSITION OF Mn3Ga1-xAlxC (x ≤ 0.05)

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-159-C8-160
Author(s):  
T. Suzuki ◽  
T. Kanomata ◽  
T. Kaneko
Keyword(s):  
Thermal Expansion ◽  
Magnetic Transition
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