4,228 research outputs found
Metamorphism of the Oddanchatram anorthosite, Tamil Nadu, South India
The Oddanchatram anorthosite is located in the Madurai District of Tamil Nadu, near the town of Palni. It is emplaced into a granulite facies terrain commonly presumed to have undergone its last regional metamorphism in the late Archean about 2600 m.y. The surrounding country rock consists of basic granulites, charnockites and metasedimentary rocks including quartzites, pelites and calc-silicates. The anorthosite is clearly intrusive into the country rock and contains many large inclusions of previously deformed basic granulite and quartzite within 100 meters of its contact. Both this intrusion and the nearby Kaduvar anorthosite show evidence of having been affected by later metamorphism and deformation
Superconductivity of lanthanum revisited: enhanced critical temperature in the clean limit
The thickness dependence of the superconducting energy gap
of double hexagonally close packed (dhcp) lanthanum islands grown on W(110) is
studied by scanning tunneling spectroscopy, from the bulk to the thin film
limit. Superconductivity is suppressed by the boundary conditions for the
superconducting wavefunction at the surface and W/La interface, leading to a
linear decrease of the critical temperature as a function of the inverse
film thickness. For thick, bulk-like films, and are
40% larger as compared to literature values of dhcp La measured by other
techniques. This finding is reconciled by examining the effects of surface
contamination as probed by modifications of the surface state, suggesting that
the large originates in the superior purity of the samples investigated
here.Comment: 14 pages, 7 figure
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