University of California at Berkeley – Physics Department – Hellman Lab Application of “Calorimetry-on-a- Chip” Technology to Heat Capacities of Quenched High Pressure Samples David W. Cooke, Frances Hellman Department of Physics, University of California, Berkeley Alexandra Navrotsky, Maria Dorogova, Charles E. Lesher Thermochemistry Facility and Dept. of Geology, University of California, Davis COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab The Earth’s Mantle Seismic 670km Chemical change 1000km D” 1800km Wikipedia image based on elements of an illustration by USGS. Gu, et al. J. geophys. Res., 106, 11,169-11,199 (2001). COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Constituents of Mantle Primarily silicates Fe,Mg majority of composites Al,Ni,Ca,Cd,Co minority “dopants” High pressure and high temperature yields complicated phase diagram of novel crystal structures –Spinel (γ) –Modified Spinel (β) –Perovskite –Post-perovskite Navrotsky. Prog. Solid St. Chem. 17, (1987). COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Constituents of Mantle (Mg,Fe) 2 SiO 4 Spinel Fe,Mg Si O O Fe,Mg (Mg,Fe)SiO 3 Perovskite Illustrations courtesy of Dr. Helmut Föll at University of Kiel - COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Synthesizing in the Lab Multi-anvil cell (<~ 27 GPa) Diamond anvil cell (<~ 200 GPa) –X-ray/IR spectroscopy, conductivity, compressibility –P-V-T, K, μ, more The first diamond-anvil cell, fabricated by Charles Weir and Alvin Van Valkenburg NIST - Navrotsky. Prog. Solid St. Chem. 17, (1987). COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Fe v. Mg Silicates Hazen, R. Science 259, (1993). COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab “Calorimeter on a Chip” Specific heat of thin films –100nm ~= 5µg –2K - 500K –0T - 8T Information gained: –Thermodynamics Decomposition Magnetic transitions Electrical changes 2006 APS Keithley Instrumentation Award COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Device Simulation Chi^2/DoF E-8 R^ ParameterValueError y E E-5 A E-5 t E-5 COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Device Simulation COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Proof of Principle COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Proof of Principle COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab COMPRES Proposal Multi-anvil and/or diamond-anvil cell experiments –Thermal contact –Sample size –Crystal shape Magnetic transitions in high pressure minerals –Test case – Fe 2 SiO 4 spinel Data across an Mg-Fe substituted series –(Fe,Mg) 2 SiO 4 olivine and/or spinel phases –(Mg,Fe)O magnesiowustites COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab COMPRES Proposal Used indium in past –Low melting point, but not good for metastable materials Silver paint –Reproducibility? Multi-anvil and/or diamond-anvil cell experiments –Thermal contact –Sample size –Crystal shape COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab COMPRES Proposal Multi-anvil and/or diamond-anvil cell experiments –Thermal contact –Sample size –Crystal shape Sample Size –Data on large devices (CoO) Addenda (Cu/LSN) = ~50 μJ Ag Addenda = ~100 μJ Sample = ~200 μJ Sample Size –Data on regular devices Addenda (LSN) = ~3 μJ Copper Addenda = ~2 μJ Sample = ~2 μJ COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab COMPRES Proposal Multi-anvil and/or diamond-anvil cell experiments –Thermal contact –Sample size –Crystal shape Magnetic transitions in high pressure minerals –Test case – Fe 2 SiO 4 spinel Data across an Mg-Fe substituted series –(Fe,Mg) 2 SiO 4 olivine and/or spinel phases –(Mg,Fe)O magnesiowustites COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Fe 2 SiO 4 Spinel Why Fe 2 SiO 4 Spinel? –Relatively low pressure of formation (~8GPa) Larger quantity of sample Multi-anvil apparatus (Charles Lesher’s lab) –Relevant to mantle physics –Potential Mg/Fe substitutional analysis –Iron silicate – we expect a magnetic transition –Fe 2+ v. Fe 3+ – potential electronic interactions? COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Fe 2 SiO 4 Spinel K. Suito et al. Proc. 9 th AIRAPT Intl. High P. Conference (1983). COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Fe 2 SiO 4 Spinel COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Fe 2 SiO 4 Spinel COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab COMPRES Proposal Multi-anvil and/or diamond-anvil cell experiments –Thermal contact –Sample size –Crystal shape Magnetic transitions in high pressure minerals –Test case – Fe 2 SiO 4 spinel Data across an Mg-Fe substituted series –(Fe,Mg) 2 SiO 4 olivine and/or spinel phases –(Mg,Fe)O magnesiowustites COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Future Work Diamond Anvil Cell Sample Capability –Develop reliable method for ~10μg sample –Consistency of silver paint? Fe 2 SiO 4 Spinel –Can we factor out the magnetic entropy –Why is the magnetic transition so much more broad? –Substitutional (Fe,Mg) 2 SiO 4 series –Decomposition enthalpy Other materials of geophysical applications –(Mg,Fe)O magnesiowustites –(Mg,Fe)SiO 3 perovskites –High pressure phases in zirconia and titania COMPRES Calorimetry on a Chip Workshop – March 15, 2007

University of California at Berkeley – Physics Department – Hellman Lab Thanks to: Frances Hellman Alex Navrostsky Masha Dorogova Charles Lesher Department of Energy Lawrence Berkeley National Lab University of California – Berkeley University of California – Davis Oak Ridge National Laboratory Ray Jeanloz Daniel Queen Erik Helgren COMPRES Calorimetry on a Chip Workshop – March 15, 2007