Publications

@article{murri_role_2022,

title = {The role of symmetry-breaking strains on quartz inclusions in anisotropic hosts: Implications for Raman elastic geobarometry},

author = {M. Murri and J. P. Gonzalez and M. L. Mazzucchelli and M. Prencipe and B. Mihailova and R. J. Angel and M. Alvaro},

url = {https://www.sciencedirect.com/science/article/pii/S0024493722001256},

doi = {10.1016/j.lithos.2022.106716},

issn = {0024-4937},

year  = {2022},

date = {2022-08-01},

urldate = {2022-08-01},

journal = {Lithos},

volume = {422-423},

pages = {106716},

abstract = {Raman elastic geobarometry for mineral host-inclusion systems is used to determine the strains acting on an inclusion still entrapped in its host by measuring its Raman wavenumber shifts which are interpreted through the phonon-mode Grüneisen tensors of the inclusion phase. The calculated inclusion strains can then be used in an elastic model to calculate the pressure and temperature conditions of entrapment. This method is applied frequently to host inclusion systems where the host is almost elastically isotropic (e.g. garnet) and the inclusion is elastically anisotropic (e.g. quartz and zircon). In this case, when the entrapment occurs under hydrostatic conditions the host will impose isotropic strains on the inclusion which in turn will develop non-hydrostatic stress. In this scenario the symmetry of the inclusion mineral is preserved and the strains in the inclusion can be measured via Raman spectroscopy using the phonon-mode Grüneisen tensor approach. However, a more complex situation arises when the host-inclusion system is fully anisotropic, such as when a quartz inclusion is entrapped within a zircon host, because the symmetry of the inclusion can be broken due to the external anisotropic strain field imposed on the inclusion by the host, which in turn will modify the phonon modes. We therefore calculated the strain states of quartz inclusions entrapped in zircon hosts in multiple orientations and at various geologically relevant pressure and temperature conditions. We then performed ab initio Hartree-Fock/Density Functional Theory (HF/DFT) simulations on α-quartz in these strain states. These HF/DFT simulations show that the changes in the positions of the Raman modes produced by strains that are expected for symmetry broken quartz inclusions in zircon are generally similar to those that would be seen if the quartz inclusions remained truly trigonal in symmetry. Therefore, the use of the trigonal phonon-mode Grüneisen tensor to determine the inclusion strains does not lead to geologically significant errors in calculated quartz inclusion entrapment pressures in zircon.},

keywords = {ab-initio, Crystallography, Density Functional Theory, DFT, Elastic anisotropy, Elastic thermobarometry, Raman spectroscopy, Raman thermobarometry},

pubstate = {published},

tppubtype = {article}

}

@article{murri_raman_2018,

title = {Raman elastic geobarometry for anisotropic mineral inclusions},

author = {Mara Murri and Mattia Luca Mazzucchelli and Nicola Campomenosi and Andrey V. Korsakov and Mauro Prencipe and Boriana D. Mihailova and Marco Scambelluri and Ross John Angel and Matteo Alvaro},

url = {https://doi.org/10.2138/am-2018-6625CCBY},

doi = {10.2138/am-2018-6625CCBY},

issn = {0003004X},

year  = {2018},

date = {2018-11-01},

urldate = {2018-11-01},

journal = {American Mineralogist},

volume = {103},

number = {11},

pages = {1869--1872},

keywords = {ab-initio, Density Functional Theory, Deviatoric stress, DFT, Elastic anisotropy, Elastic thermobarometry, metamorphic rocks, Raman spectroscopy, Raman thermobarometry},

pubstate = {published},

tppubtype = {article}

}

@article{Milani2017,

title = {Thermo-elastic behavior of grossular garnet at high pressures and temperatures},

author = {S. Milani and Ross John Angel and L. Scandolo and M. L. Mazzucchelli and T. B. Ballaran and S. Klemme and M. C. Domeneghetti and R. Miletich and K. S. Scheidl and M. Derzsi and K. Tokár and M. Prencipe and M. Alvaro and F. Nestola},

url = {https://doi.org/10.2138/am-2017-5855},

doi = {10.2138/am-2017-5855},

issn = {19453027},

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

journal = {American Mineralogist},

volume = {102},

number = {4},

pages = {851--859},

abstract = {© 2017 by Walter de Gruyter Berlin/Boston 2017. The thermo-elastic behavior of synthetic single crystals of grossular garnet (Ca 3 Al 2 Si 3 O 12 ) has been studied in situ as a function of pressure and temperature separately. The same data collection protocol has been adopted to collect both the pressure-volume (P-V) and temperature-volume (T-V) data sets to make the measurements consistent with one another. The consistency between the two data sets allows simultaneous fitting to a single pressure-volume-temperature Equation of State (EoS), which was performed with a new fitting utility implemented in the latest version of the program EoSFit7c. The new utility performs fully weighted simultaneous fits of the P-V-T and P-K-T data using a thermal pressure EoS combined with any P-V EoS. Simultaneous refinement of our P-V-T data combined with that of K T as a function of T allowed us to produce a single P-V-T-K T equation of state with the following coefficients: V 0 =1664.46(5)Å 3 K TO =166.57(17)GPa and K′=4.96(7)α (300K,1bar) =2.09(2)×10 -5 K -1 with a refined Einstein temperature (θ E ) of 512 K for a Holland-Powell-type thermal pressure model and a Tait third-order EoS. Additionally, thermodynamic properties of grossular have been calculated for the first time from crystal Helmholtz and Gibbs energies, including the contribution from phonons, using density functional theory within the framework of the quasi-harmonic approximation.},

keywords = {ab-initio, Density Functional Theory, DFT, Elastic thermobarometry, equations of state, high-pressure, high-temperature, thermal expansion, thermodynamics},

pubstate = {published},

tppubtype = {article}

}