Reid Cooper - Academia.edu (original) (raw)

Papers by Reid Cooper

EGU General Assembly 2010, held 2 …, 2010

Our ability to observe and interpret reasonably the tectonics of icy satellites hinges on our und... more Our ability to observe and interpret reasonably the tectonics of icy satellites hinges on our understanding of the vis-coelastic and plastic rheologies and microstructural evolution of the material comprising their icy outer shells. The morphological diversity observed on the surfaces of the ...

Physics and Chemistry of Minerals

9th International Conference on Advanced Thermal Processing of Semiconductors, RTP 2001

... of the Electrochemical Society (March 2001) [7] Yu Bykov, A. Eremeev, V. Flyagin, V. Kaurov, ... more ... of the Electrochemical Society (March 2001) [7] Yu Bykov, A. Eremeev, V. Flyagin, V. Kaurov, A. Kuftin, A. Luchinin, O.Malygin, I. Plotnikov, V. Zapevalov, in Proc. ... of Ion Implant TechIogv (2000) [ 1 11 W. Lerch, B. Bayha, DF Downey, EA Arevalo. in Proc. ...

Here we report Atom Probe Tomography (APT) analyses of grain and phase boundaries of lab... more Here we report Atom Probe Tomography (APT) analyses of grain and phase boundaries of laboratory-deformed, fine-grained mixtures of clinopyroxene and olivine (Zhao, et al., 2019).  The experiments show that the mixtures deform much more rapidly than either mineral endmember.  This enhanced deformation in the two-phase material is due to stress-driven reactions at the phase boundaries. Lower effective viscosities of phase mixtures may be critical to the initiation of plate tectonics and the formation of mantle shear zones.The hypothesis presented here is that the ‘bulk rock’ – a wehrlite – deforms rapidly because conversion of one phase to the other occurs at phase boundaries (e.g., Sundberg & Cooper, 2008).  In this model, grain-scale transport of the shared (slowly-diffusing) mineralogical component Si4+ is not required.  The near-boundary gradients of olivine-insoluble ions are presented as evidence of the phase transformation which either dissolves olivine into clinopyroxene or vice versa.  The resolving power of the APT makes it a promising tool for investigating the microphysics of rock deformation, bridging the atomic scale all the way to the plate-tectonic scale.References: Sundberg M, Cooper RF (2008) Crystallographic preferred orientation produced by diffusional creep of harzburgite: effects of chemical interactions among phases during plastic flow. J Geophys Res Solid Earth 113(12):B12208. Zhao N, Hirth G, Cooper RF, Kruckenberg SC, Cukjati J (2019) Low viscosity of mantle rocks linked to phase boundary sliding. Earth Planet Sci Lett 517:83–94.

G.B. Cook & R.F. Cooper, Iron concentration & the physical processes of dynamic oxidation in an a... more G.B. Cook & R.F. Cooper, Iron concentration & the physical processes of dynamic oxidation in an alkaline earth aluminosilicate glass, Am. Mineral. 85, 397-406 (2000).

Goldschmidt2021 abstracts, 2021

International Conference on Plasma Science (papers in summary form only received), 1995

Summary form only given, as follows. Numerous claims have been made of observations that microwav... more Summary form only given, as follows. Numerous claims have been made of observations that microwave heating of ceramics promotes faster processing or solid state reactions (e.g., sintering, bonding, tracer ion diffusion) than conventional furnace heating. These claims are controversial due to the absence of a verifiable theoretical explanation as well as questions on the interpretation of sample temperature measurements obtained

Physics and Chemistry of Minerals, 2019

The chemical widths of grain and phase boundaries in deformed wehrlite (olivine-clinopyroxene; Ol... more The chemical widths of grain and phase boundaries in deformed wehrlite (olivine-clinopyroxene; Ol-Cpx) aggregates are characterized by atom probe tomography (APT), a (laser-assisted) field evaporation technique employing time-of-flight mass spectrometry. The wehrlite was deformed to high finite strain in diffusion creep: The effective viscosity measured for the wehrlite is approximately an order of magnitude lower than that of either end-member aggregate; further, phase ordering, in which the spatial density of Ol-Cpx phase boundaries increases with accumulated strain, characterizes the deformation (Zhao et al. in Earth Planet Sci Lett 517:83-94, 2019). The mechanical results imply that the transport properties of the phase boundaries-dictated by their structure and composition-differ from those of grain boundaries. Our APT data show that, indeed, the chemical widths of crystalline Ol-Cpx phase boundaries-3.1-6.6 nm, depending on the element used for their characterization-are up to a factor of two greater than the chemical widths of crystalline Ol-Ol and Cpx-Cpx grain boundaries. Careful statistical analyses of the APT data reveal that the near-boundary compositional profiles of the presented Ol-Cpx phase boundary are consistent with-indeed, evidence for-the rheological model in which diffusion creep is rate-limited by the (mechanism-required) interfacial reactions at the Ol-Cpx phase boundaries. Such an analysis is unavailable by current electron beam/X-ray spectrometry approaches, which have not the requisite spatial precision. APT application to nanometer-scale problems in silicate petrology is challenging, particularly because signal overlap is caused by the evaporation of polyion species. We carefully outline the procedures used to acquire and discriminate the data in order to address the challenges of signal overlap.

MRS Proceedings, 2002

Electromagnetic heating provides a novel alternative to “illumination-based” rapid thermal proces... more Electromagnetic heating provides a novel alternative to “illumination-based” rapid thermal processing techniques. Exposure to radiation, in the RF and microwave frequency regimes, rapidly heats silicon (∼125°C/sec) to temperatures in excess of 1000°C without the use of a susceptor. These ramp rates make this technology suitable for the activation of shallow implanted dopants, and satisfaction of the 100 nm technology node has been achieved. Furthermore, the presence of high frequency electric fields creates ponderomotive forces that may alter the kinetics of dopant activation and diffusion. These additional driving forces could, once fully understood, lead to an enhanced activation mechanism that activates sufficient dopants to satisfy the 70 nm technology node at temperatures less than 1000°C.

Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1994

The object of this work is to develop a fabrication process to produce a nonmetallic magnetic har... more The object of this work is to develop a fabrication process to produce a nonmetallic magnetic hard disk with a thin magnetic layer that features small magnetic spinel grains suspended in a host nonmetallic medium. Plasma source ion implantation (PSII) of oxygen into iron-doped magnesium aluminosilicate (MAS) glass and simultaneous implantation of iron and oxygen into calcium aluminosilicate (CAS) glass have been investigated. The implant energy used in these experiments was 30 keY and the oxygen dose was estimated to be I X 10 17 ions/cm 2 for both MAS and CAS glasses. The results showed that PSII of oxygen into MAS glass increased the iron ions' binding energy, probably due to the valence state conversion of Fe 2 + to Fe H. The post anneal yielded a thin two-phase layer near the surface. consisting of Mg-Fe-Si-O crystals and the glass matrix. A slight ~egregati()n of Fe in the implanted region took place during the anneal, because of the out-diffusion llf Fe c. ions from the substrate to the oxygen-rich region. The simultaneous implantation of iron and oxygen into CAS glass resulted in the formation of an iron oxide. Fe20,.

Microscopy and Microanalysis, 2015

Journal of Microwave Power and Electromagnetic Energy, 2007

![Research paper thumbnail of Melt Inclusions from the Gal�pagos Plume: Clues to the Origin of `Ghost Plagioclase](https://a.academia-assets.com/images/blank-paper.jpg)

Journal of Microelectromechanical Systems, 2002

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS)

International Geophysics, 1994

Publisher Summary This chapter discusses melt migration and related attenuation in equilibrated p... more Publisher Summary This chapter discusses melt migration and related attenuation in equilibrated partial melts. Anelasticity associated with the migration of the melt phase in synthetic olivine–basalt partial melts is examined experimentally in this chapter. Newtonian-viscous, texturally (quasi)equilibrated partial-melt aggregates were subjected to four-point flexural loading at elevated temperature (1070–1200°C); the creep response was characterized by a substantial, decelerating transient. The fact that melt-free grain boundaries characterize the steady-state microstructure of partial melts of upper-mantle composition supports the idea that dilatational anelasticity may be the unique dynamic signature of partial melting under conditions that produce a low melt fraction and that disallow the fracture of the crystalline residuum. The melt-migration attenuation effect noted in the experiments is sensitive to the magnitude of applied strain because of the coupling of the melt migration to the deformation kinetics of the crystalline residuum. Thus, further experimentation into the attenuation behavior of partial melts at seismic/subseismic frequencies requires working at low-strain amplitudes.