Theoretical modeling of minerals under high pressure

• Grant number: 09/14082-3
• Support Opportunities: Research Projects - Thematic Grants
• Start date: March 01, 2010
• End date: February 28, 2013
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Joao Francisco Justo Filho
• Grantee: Joao Francisco Justo Filho
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Pesquisadores principais: Lucy Vitoria Credidio Assali
• Associated researchers: Joelson Cott Garcia ; Wanda Valle Marcondes Machado
• Associated scholarship(s): 10/19697-3 - Properties of iron impurities in magnesium oxide, BP.PD

Abstract

The study of materials properties under high pressure allowed, in the last decades, developments in several fields, ranging from metallurgy to astrophysics. Specifically in geophysics, high pressure experiments try to reproduce the thermodynamic conditions in which minerals are subjected in the Earth´s interior. In the last few years, one of the most investigated subjects in geophysics is related to the phenomenology of the lower mantle, which comprises depths between 670 and 2700 Km, and pressures between 20 and 130 GPa, respectively. Knowing the properties of the mantle is fundamental to determine a number of relevant properties of the Earth, such as its chemical composition, and the geodynamics and tectonic plate evolution. Most of the known information on the Earth´s mantle is obtained indirectly, using information from seismic wave propagation across the mantle. Measurements on seismic waves lead to knowledge on the density and elastic properties of the mantle, but the challenge is to use such information to identify the chemical composition of the mantle. To build compositional models of the mantle, it is important to correlate the elastic properties of the mantle with those from known materials, which were obtained in laboratory under thermodynamic conditions of the mantle, i.e. high temperatures and pressures. In such context, theoretical modeling, based on atomistic simulations, can be an important tool to study these materials. Earth´s mantle is primarily composed of oxides (MgO e MgSiO_3), with a still undetermined concentration of iron. However, important question on the iron incorporation in those minerals are still open. An understanding on how iron interacts in those minerals is fundamental for the development of more reliable compositional models of the lower mantle. The major goal of this project is to establish a research group to develop atomistic simulations, based on ab initio models, to study the high-pressure properties of minerals. One of the major focus of this project will be on the properties iron in those minerals. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MARCONDES, M. L.; JUSTO, J. F.; ASSALI, L. V. C.. Carbonates at high pressures: Possible carriers for deep carbon reservoirs in the Earth's lower mantle. Physical Review B, v. 94, n. 10, SEP 23 2016. (09/14082-3)

MARCONDES, M. L.; JUSTO, J. F.; ASSALI, L. V. C.. Carbonates at high pressures: Possible carriers for deep carbon reservoirs in the Earth's lower mantle. PHYSICAL REVIEW B, v. 94, n. 10, p. 9-pg., 2016-09-23. (09/14082-3)

JUSTO, J. F.; MORRA, G.; YUEN, D. A.. Viscosity undulations in the lower mantle: The dynamical role of iron spin transition. Earth and Planetary Science Letters, v. 421, p. 20-26, JUL 1 2015. (09/14082-3)