Dr. Richard Secco
Ph.D. Western University, 1988
Office: BGS 0178
Labs: BGS 0127, 0132
Phone: 519-661-2111 x.84079
My research interest lie in Mineral Physics and Materials Science. Each study in these two disciplines finds application to specific and different physico-chemical problems/investigations. The unifying theme that binds them is my primary goal of understanding the effects of high pressures and temperatures on solids and liquids, particularly as these parameters perturb and present the promise of control of physical properties. Knowledge of physical property behavior is pivotal for understanding many Earth processes as well as for tailoring specific responses in materials for applications. Many of these studies utilize equipment in the UWO Experimental High Pressure / Temperature Mineral Physics / Materials Science Laboratory.
- Balog, P.S., Secco, R.A., D.C. Rubie, D.C. and Frost, D.J., Equation of State of Liquid Fe-10wt%S: Implications for the Metallic Cores of Planetary Bodies, submitted to Journal of Geophysical Research, accepted June 21, 2002, in press.
- Liu, H., Secco, R.A., Imanaka, N., Rutter, M.D., Adachi, G., Uchida, T., Ionic to Electronic Dominant Conductivity in Al2(WO4)3 at High Pressure and High Temperature, Journal of Physics and Chemistry of Solids, accepted May 28, 2002, in press.
- Secco, R.A., Liu, H., Imanaka, N., Adachi, G., Anomalous Ionic Conductivity of Sc2(WO4)3 Mediated by Structural Changes at High Pressures and Temperatures Journal of Physics: Condensed Matter, in press, 2002.
- Secco, R.A., Rutter, M.D., Balog, S.P., Liu, H., Rubie, D.C., Uchida, T., Frost, D., Wang, Y., Rivers, M., Sutton, S., Viscosity and Density of Fe-S Liquids at High Pressures, Journal of Physics: Condensed Matter, in press, 2002.
- Uchida, T., Wang, Y., Rivers, M.L., Sutton, S.R., Weidner, D.J., Vaughan, M.T., Chen, J., Li, B., Secco, R.A., Rutter, M.D., Liu, H., A large Volume Press Facility at the APS: Diffraction and Imaging Studies on Materials Relevant to the Cores of Planetary Bodies, Journal of Physics: Condensed Matter, in press, 2002.
Earth Sciences 1085: Introduction to Geophysics (Fall 2001)
Earth Sciences 3321: Physics of the Earth I
Earth Sciences 4424: Advanced Mineral Physics
Geophysics 9507: Aspects of High Pressure Geophysics
Geophysics 9572: Physics of the Earth
Geophysics 9574: Seismic Exploration (with Lalu Mansinha)
Innocent Ezenwa - Geophysics Ph.D. candidate
Understanding electrical transport in a metal such as Iron which is the dominant element in the core and other similar elements at core condition is important in understanding the transport of heat from the core to the mantle. In all metals, the motion of delocalized electrons contributes most to the heat transport than phonons. The heat conductivity of a metal relates to its electrical conductivity by Widemann-Fraz law. My project aims at investigating the possibility of invariance in the electrical resistivity of elements (Cu, Zn, Ni and Mn) at melt which can compare and contrast the role played by the incomplete 3d orbital in the electrical and thermal conductivity of liquid Iron. The result of the research will constrain the quantity of heat emitted at the inner-core boundary of the core which is dominantly pure Iron in composition.
My research aims to determine the mechanisms responsible for earthquakes that occur deep (up to 700 km) within the earth. At depths below about 60 km the pressure and temperature conditions are such that rocks are expected to deform instead of fracturing. This process is thought to be associated with phase transformations (abrupt changes in mineral structure) generated by the pressure and temperature environment. My thesis involves subjecting minerals thought to be associated with deep seismicity to the pressure and temperature conditions of the upper mantle and measuring acoustic emission signals linked to phase transformations.
Ryan Sawyer - Geophysics Ph.D. candidate
Silicate melts play an important role in the formation and evolution of terrestrial planets. Silicate glasses are often used as analogues for melts. Being amorphous solids, a wide variety of analytical techniques can be used to study their structure and properties. My project focuses on the how the structures of potassium silicate and potassium aluminosilicate glasses change with variations in composition, pressure and temperature. X-ray Photoelectron Spectroscopy (XPS) is used to measure abundances of different structural types of oxygen atoms (Bridging, Non-Bridging and Free Oxygen atoms).
Dr. Wenjun Yong - Lab Manager
My research interests in a broad sense are experimental petrology and mineral physics. Within this framework, I am exploring the chemical and physical properties of minerals under mantle conditions and their pressure and/or temperature induced phase transitions that have potential applications in mineralogy, material sciences, geological and planetary sciences. This involves experimental synthesis of high pressure phases, calorimetric measurements, high pressure and high temperature phase equilibrium experiments, equation of state determination, new phase identification, and thermodynamic calculations of phase transition boundaries. Besides, I am also interested in other research topics such ultra-high pressure metamorphic rocks, core-mantle differentiation and early evolution of Earth and other terrestrial planets.