This readme.txt file was generated on by ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset: Data for "Simulation of natural alteration of iron oxides in soil: conversion of synthetic ferrihydrite to hematite without artificial dopants, observed with magnetic methods" collected at the University of Minnesota between 2016 and 2020 2. Author Information Principal Investigator Contact Information Name: Dario Bilardello Institution: University of Minnesota Address: University of Minnesota Institute for Rock Magnetism Email: dario@umn.edu ORCID: Associate or Co-investigator Contact Information Name: Subir K. Banerjee Institution: University of Minnesota Address: Email: ORCID: Associate or Co-investigator Contact Information Name: Michael Volk Institution: University of Minnesota Address: Email: ORCID: Associate or Co-investigator Contact Information Name: Jennifer A. Soltis Institution: University of Minnesota Address: Email: ORCID: Associate or Co-investigator Contact Information Name: R Lee Penn Institution: University of Minnesota Address: Email: ORCID: 3. Date of data collection: 2016-2020 4. Geographic location of data collection: All magnetic data was collected at the Institute for Rock Magnetism, Minneapolis, MN 5. Information about funding sources that supported the collection of the data: Sponsorship: Research was funded through the Instrumentation and Facilities program of the National Science Foundation Earth Sciences Division (NSF/EAR 1642268) -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: https://creativecommons.org/publicdomain/zero/1.0/ 2. Links to publications that cite or use the data: Bilardello, D., Banerjee, S.K., Volk, M., Soltis, J.A., and R. Lee Penn (2020). Simulation of natural alteration of iron oxides in soil: conversion of synthetic ferrihydrite to hematite without artificial dopants, observed with magnetic methods. Submitted to Geochem., Geophys., Geosyst. 3. Links to other publicly accessible locations of the data: n/a 4. Recommended citation for the data: --------------------- DATA & FILE OVERVIEW --------------------- 1. File List A. Filename: Goethite_test.xlsx Short description: Goethite tests Size/Format: 216.1Kb Microsoft Excel 2007 Variables (headers) = 5 Temperature (K): kelvin Field (T): tesla Magnetization (Am^2/kg) step = post/pre AF, FC, Post_TH dir = heat or cool Each tab contains single specimen data named after the experimental annealing step between 0 and 32 hours. Specimen duplicates are identified as (1) and (2). Step: FC indicates field cooled (in-field) magnetization; pre-AF indicates magnetic remanence measured before alternating filed demagnetization; post-AF indicates magnetic remanence measured after AF demagnetization; post_TH indicates magnetic remanence measured after heating to 400 K. Dir: heat/cool indicate whether the magnetization was measured upon heating/cooling, respectively. B. Filename: Hysteresis.xlsx Short description: Magnetic Hysteresis Size/Format: 407.8Kb Microsoft Excel 2007 Variables (headers) = 2 then 5 on the results tabs B (T) M (Am^2/kg) Annealing T (K) Ms (Am^2/kg) Mr (Am^2/kg) Bc (mT) Each tab contains single specimen raw, uncorrected hysteresis loop data (field (B) and magnetization (M)), and are named after the experimental annealing step between 0 and 32 hours and the temperature at which they were acquired (5 K and 300 K). The tabs named "results" contain hysteresis parameters (saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Bc) obtained from the individual specimen loops at 5 K and 300 K, separated by annealing step. C. Filename: Mossbauer.xlsx Short description: Mössbauer Size/Format: 1.147Mb Microsoft Excel 2007 Variables (headers) = v (mm/s) data v_sum (mm/s) sum(fit) v_site1 fit_site1 v_site2 fit_site2 v_site3 fit_site3 v_site4 fit_site4 Each tab contains the data for a single specimen, named after the annealing step between 0 and 32 hours, and the temperature at which it was measured. Note the higher resolution of the fitted data (i.e., missing values in v (mm/s) and data columns. In general, v represents the velocity of the Mössbauer drive in mm/s. v (mm/s), data: The raw velocity and raw gamma quantum counts (normalized to the max value) v_sum (mm/s), sum(fit): velocity and calculated data of the sum of the best fits for all sites v_site_n, fit_site_n: velocity and best fit of the site n, where n is the number of sites. D. Filename: pXRD.xlsx Short description: pXRD Size/Format: 215.1Kb Microsoft Excel 2007 Variables (headers) = 2 2Theta I Each tab contains the diffraction angle (2-Theta) and corresponding intensity data for a specimen at 0, 3, or 32 hours of annealing. E. Filename: Susceptibility.xlsx Short description: Magnetic Susceptibility Size/Format: 33.14Kb Microsoft Excel 2007 Variables (headers) = 8 Temperature (K) X'(1 Hz) (m3/kg) X"(1 Hz) (m3/kg) X'(10 Hz) (m3/kg) X"(10 Hz) (m3/kg) X'(100 Hz) (m3/kg) X"(100 Hz) (m3/kg) X'_fd% Each tab contains single specimen data named after the experimental annealing step between 0 and 32 hours. Temperature step represents the temperature increments at which magnetic susceptibility was measured upon warming between 10 and 100 K, and for certain specimens between 10 and 300 K. X' denotes in-phase mass-normalized susceptibility, whereas X" denotes out-of-phase mass-normalized susceptibility (units of m3/kg) and acquired in frequencies of 1, 10, and 100 Hz and fields of 238.7 A/m. Measurements between 10 and 300 K were acquired in 1000 Hz and 238.7 A/m fields. X'_fd% denotes frequency-dependent in-field susceptibility for each temperature step, calculated as: (X' 1Hz- X' 100 Hz)/ X' 10 Hz * 100. 𝜋/2 (1-10 Hz) and 𝜋/2 (10-100 Hz)denote 𝜒”[viscosity]= -(𝜋/2)(𝛿𝜒’/𝛿lnf) calculated from the 1-10 Hz and 10-100 Hz 𝜒’ data, respectively. 2. Relationship between files: 3. Additional related data collected that was not included in the current data package: -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: Magnetic, pXRD, and Mössbauer metadata used in the cited study on alteration of synthetic ferrihydrite. All magnetic data was collected at the Institute for Rock Magnetism on Quantum Design MPMSs (XL and 5S) and comprises magnetic susceptibility (in-phase and out-of-phase) as a function of temperature (10-300K) and frequency (1-100 Hz), hysteresis loops measured at 5K and 300 K, and magnetic remanence data (pTRM, temperature and AF demagnetized, the "goethetite test") collected between 400 and 10 K. Powder X-ray diffraction (pXRD) was performed on a PANalytical X’Pert PRO X-ray diffractometer equipped with a Co source (0.17909 nm) and an X’Celerator detector in the range of 10˚ to 90˚ in 2θ in 0.017˚ steps with an integration time of 100 seconds per step, in the Department of Chemistry, University of Minnesota. Mössbauer spectra were acquired at the Institute for Rock Magnetism on a CCR instrument using a 25mCi 57Co source in a Rh matrix using a constant acceleration drive and transmission geometry. 2. Methods for processing the data: 3. Instrument- or software-specific information needed to interpret the data: 4. Standards and calibration information, if appropriate: 5. Environmental/experimental conditions: 6. Describe any quality-assurance procedures performed on the data: 7. People involved with sample collection, processing, analysis and/or submission: