TY - THES N2 - The mixed and variable valence of iron in magnetite (Fe(III)tet[Fe(II),Fe(III)]octO42? ) give this 202 mineral unique properties that make it an important participant in redox reactions in 203 environmental systems, but the variability in its stoichiometry and other physical properties 204 complicates the determination of its effective redox potential. To address this challenge, a robust 205 method was developed to prepare working electrodes with mineral powders of diverse 206 characteristics and agarose-stabilized pore waters of controlled composition. This second-207 generation powder-disk electrode (PDEv2) methodology was used to characterize the 208 electrochemical properties of magnetite samples from a wide variety of sources (lab-synthesized, 209 commercial, and magnetically separated from environmental samples) using a sequence of 210 complementary potentiometric methods: chronopotentiometry (CP), linear polarization resistance 211 (LPR), electrochemical impedance spectroscopy (EIS), and then linear sweep voltammetry 212 (LSV). DO - 10.6083/f4752h32v DO - DOI AB - The mixed and variable valence of iron in magnetite (Fe(III)tet[Fe(II),Fe(III)]octO42? ) give this 202 mineral unique properties that make it an important participant in redox reactions in 203 environmental systems, but the variability in its stoichiometry and other physical properties 204 complicates the determination of its effective redox potential. To address this challenge, a robust 205 method was developed to prepare working electrodes with mineral powders of diverse 206 characteristics and agarose-stabilized pore waters of controlled composition. This second-207 generation powder-disk electrode (PDEv2) methodology was used to characterize the 208 electrochemical properties of magnetite samples from a wide variety of sources (lab-synthesized, 209 commercial, and magnetically separated from environmental samples) using a sequence of 210 complementary potentiometric methods: chronopotentiometry (CP), linear polarization resistance 211 (LPR), electrochemical impedance spectroscopy (EIS), and then linear sweep voltammetry 212 (LSV). T1 - Electrochemical characterization of iron minerals DA - 2020 AU - Bradley, Miranda J. L1 - https://digitalcollections.ohsu.edu/record/8050/files/Bradley.Miranda.2020.pdf PB - Oregon Health and Science University PY - 2020 ID - 8050 L4 - https://digitalcollections.ohsu.edu/record/8050/files/Bradley.Miranda.2020.pdf KW - Iron KW - Electrochemistry KW - electrochemical impedance spectroscopy KW - magnetite TI - Electrochemical characterization of iron minerals Y1 - 2020 L2 - https://digitalcollections.ohsu.edu/record/8050/files/Bradley.Miranda.2020.pdf LK - https://digitalcollections.ohsu.edu/record/8050/files/Bradley.Miranda.2020.pdf UR - https://digitalcollections.ohsu.edu/record/8050/files/Bradley.Miranda.2020.pdf ER -