Volume self-diffusion of oxygen in titanite.
نویسندگان
چکیده
منابع مشابه
Oxygen self-diffusion ‘‘fast-paths’’ in titanite single crystals and a general method for deconvolving self-diffusion profiles with ‘‘tails’’
Like most other minerals, titanite rarely if ever forms perfect crystals. In addition to the point defects that might affect lattice diffusion, there may be extended lineor planar defects along which fast diffusion could occur. During the course of an experimental study of oxygen lattice diffusion in titanite, we found that almost all of the O uptake profiles produced in natural titanite crysta...
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Oxygen diffusion in natural and synthetic single-crystal titanite was characterized under both dry and water-present conditions. For the dry experiments, pre-polished titanite samples were packed in O-enriched quartz powder inside Ag–Pd capsules, along with a fayalite–magnetite–quartz (FMQ) buffer assemblagemaintained physically separate by Ag–Pd strips. The sealed Ag–Pd capsules were themselve...
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Modulation of resistance by an external magnetic field, i.e. magnetoresistance effect, has been a long-lived theme of research due to both fundamental science and device applications. Here we report colossal positive magnetoresistance (CPMR) (>30,000% at a temperature of 2 K and a magnetic field of 9 T) discovered in degenerate semiconducting strontium titanite (SrTiO3) single crystals capped w...
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We have explored the diffusivity characteristics of radiogenic He in titanite (sphene) and have developed analytical techniques for (U–Th)/He dating of this mineral. Results of incremental He outgassing experiments performed on titanites from a variety of geological environments suggest a thermally activated volume diffusion mechanism with an activation energy of 44.6 6 3.4 (2s) kcal/mol and a ...
متن کاملOxygen self-diffusion in HfO2 studied by electron spectroscopy.
High-resolution measurement of the energy of electrons backscattered from oxygen atoms makes it possible to distinguish between (18)O and (16)O isotopes as the energy of elastically scattered electrons depends on the mass of the scattering atom. Here we show that this approach is suitable for measuring oxygen self-diffusion in HfO2 using a Hf(16)O2 (20 nm)/Hf(18)O2 bilayers (60 nm). The mean de...
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ژورنال
عنوان ژورنال: GEOCHEMICAL JOURNAL
سال: 1996
ISSN: 0016-7002
DOI: 10.2343/geochemj.30.71