Synthesis and Magnetic Characterization of Siderite ...
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Synthesis and Magnetic Characterization of Siderite Particles with Varying Morphologies: Implication for Rock Magnetic Properties Lindsay A. Hegner 1 , Jennifer H. Strehlau 1 , Becky E. Strauss 2 , Joshua M. Feinberg 2 , and R. Lee Penn 1 1 Department of Chemistry, University of Minnesota, Minneapolis, MN 2 Institute for Rock Magnetism, Department of Earth Sciences, University of Minnesota, Minneapolis, MN Results Discussion At different initial Fe(II) concentrations, there was a difference in particle morphology, particle size, and magnetic data obtained. SEM confirms radial growth texture consistent with naturally occurring siderite. XRD confirms pure siderite samples when the suspension was aged at 130 °C in the autoclave. MPMS data is inconsistent between various concentration trials and current literature. There is a shift in Néel temperature (from <40 K to >50 K) from previous literature. 2,3 Higher Fe(II) concentrations result in increased initial growth of particle seeds. This contributed to a greater variety in morphologies, but particles are smaller and have less growth due to resources being used more quickly. Lower Fe(II) concentrations result in fewer particle seeds. This contributed to less variety of morphologies but larger particles, due to more growth since resources are used slowly. Future Work Perform characterization on a siderite standard for comparison Determine if drying effects are present Conduct a time series to determine size dependency of the Néel temperature Determine single domain size Apply Mössbauer spectroscopy to determine any presence of Fe(III) Perform synthesis with different reducing agents Acknowledgements This work was supported by: 1) Frederichs, T., Von Dobeneck, T., Bleil, U., & Dekkers, M. J. (2003). Towards the identification of siderite, rhodochrosite, and vivianite in sediments by their low-temperature magnetic properties. Physics and Chemistry of the Earth, Parts A/B/C, 28(16), 669-679. 2) Pan, Y., Zhu, R., Liu, Q., Jackson, M. (2002). Low-temperature magnetic behavior related to thermal alteration of siderite. Geophys. Res. Lett, 29(23), 2087-2090. 3) Roh, Y., Zhang, C. L., Vali, H., Lauf, R. J., Zhou, J., & Phelps, T. J. (2003). Biogeochemical and environmental factors in Fe biomineralization: magnetite and siderite formation. Clays and Clay Minerals, 51(1), 83-95. 4) Qu, X. F., Yao, Q. Z., & Zhou, G. T. (2011). Synthesis of siderite microspheres and their transformation to magnetite microspheres. European Journal of Mineralogy, 23(5),759-770. 5) Romanek, C. S., Jiménez-López, C., Navarro, A. R., Sánchez-Román, M., Sahai, N., & Coleman, M. (2009). Inorganic synthesis of Fe–Ca–Mg carbonates at low temperature. Geochimica et Cosmochimica Acta, 73(18), 5361-5376. 6) Mozley, P. S., & Burns, S. J. (1993). Oxygen and carbon isotopic composition of marine carbonate concretions; an overview. Journal of Sedimentary Research, 63(1), 73-83. Introduction Siderite is an iron(II) carbonate (FeCO 3 ) mineral commonly found in a range of natural environments, including anaerobic aqueous ecosystems, systems containing biomineralization and extraterrestrial formations. 1-5 Siderite can be identified by a characteristic magnetic transition at low temperatures below 40 K. 1,2 It is important to be able to detect siderite through low temperature rock magnetic analysis due to its ability to undergo phase transformation to magnetite under certain conditions. 2 It can also complicate carbon and oxygen isotopic analyses in natural rock samples. 6 Additionally, it may greatly assist in the identification of biomineralization processes and paleoclimates. 4 The goal of this project was to synthesize and characterize siderite particles of varying morphologies and grain sizes. Using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Magnetic Properties Measurement System (MPMS) analyses, we aim to determine trends between particle morphology, grain size, and rock magnetic properties. Experimental The following synthetic procedure 4 was completed at varying initial Fe(II) concentrations: 0.033 M, 0.067 M, and 0.10 M. One solution of 0.2 M sodium carbonate (Na 2 CO 3 ) was combined with a solution containing 0.2 M ascorbic acid and varying concentrations of ferrous sulfate (FeSO 4 ) in an autoclave with a total volume of 60 mL. Particle suspension was aged for 4 hours at 130 °C. Once removed from oven, suspension was cooled overnight to room temperature. The suspension was then purified using dialysis until particles settled from solution. 20 30 40 50 60 70 80 Intensity 2 Theta Siderite Siderite PDF Ferrihydrite PDF 20 30 40 50 60 70 80 Intensity 2 Theta Siderite Siderite PDF 20 30 40 50 60 70 80 Intensity 2 Theta Siderite Siderite PDF 20 30 40 50 60 70 80 Intensity 2 Theta Siderite Siderite PDF 0 2 4 6 8 10 12 14 0 50 100 150 200 250 300 M (10 -3 Am 2 /kg) Temperature (K) FC ZFC 0 5 10 15 20 0 50 100 150 200 250 300 M (10 -6 Am 2 /kg) Temperature (K) Cooling Warming 0.15 0.25 0.35 0.45 0.55 0.65 0 50 100 150 200 250 300 M (Am 2 /kg) Temperature (K) 0 0.1 0.2 0.3 0.4 0.5 0.6 0 50 100 150 200 250 300 M (Am 2 /kg) Temperature (K) 0 1 2 3 4 5 6 0 50 100 150 200 250 300 M (10 -3 Am 2 /kg) Temperature (K) FC ZFC 0 5 10 15 20 25 30 35 40 45 0 50 100 150 200 250 300 M (10 -6 Am 2 /kg) Temperature (K) Cooling Warming 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0 50 100 150 200 250 300 M (Am 2 /kg) Temperature (K) 0 1 2 3 4 5 6 7 8 9 10 0 50 100 150 200 250 300 M (10 -3 Am 2 /kg) Temperature (K) FC ZFC 0 5 10 15 20 25 30 35 0 50 100 150 200 250 300 M (10 -6 Am 2 /kg) Temperature (K) Cooling Warming 0 0.1 0.2 0.3 0.4 0.5 0.6 0 50 100 150 200 250 300 M (Am 2 /kg) Temperature (K) ~59 K 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 50 100 150 200 250 300 M (10 -3 Am 2 /kg) Temperature (K) FC ZFC 0 2 4 6 8 10 12 14 16 18 0 50 100 150 200 250 300 M (10 -6 Am 2 /kg) Temperature (K) Cooling Warming 0.067 M at 90 °C 0.033 M at 130 °C 0.067 M at 130 °C 0.10 M at 130 °C Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from NSF through the MRSEC program. Undergraduate Research Opportunity Program Institute for Rock Magnetism National Science Foundation References SEM XRD Saturation Magnetization Field Cooled – Zero Field Cooled Remanence Room Temperature Remanence Figure 1: Analysis of siderite particles at various temperatures and initial Fe(II) concentrations. (left to right) Results of SEM, XRD, saturation magnetization, field cooled and zero-field cooled remanence and room temperature remanence. (top to bottom) Concentration and temperature series including 0.067 M Fe(II) at 90 °C, 0.033 M Fe(II) at 130 °C, 0.067 M Fe(II) at 130 °C and 0.10 M Fe(II) at 130 °C. ~54 K ~57 K ~54 K ~60 K ~59 K ~60 K ~62 K
Transcript of Synthesis and Magnetic Characterization of Siderite ...
Synthesis and Magnetic Characterization of Siderite Particles with Varying
Morphologies: Implication for Rock Magnetic Properties Lindsay A. Hegner1, Jennifer H. Strehlau1, Becky E. Strauss2, Joshua M. Feinberg2, and R. Lee Penn1
1Department of Chemistry, University of Minnesota, Minneapolis, MN 2Institute for Rock Magnetism, Department of Earth Sciences, University of Minnesota, Minneapolis, MN
Results
Discussion
At different initial Fe(II) concentrations, there was a difference in particle
morphology, particle size, and magnetic data obtained.
SEM confirms radial growth texture consistent with naturally occurring siderite.
XRD confirms pure siderite samples when the suspension was aged at 130 °C in
the autoclave.
MPMS data is inconsistent between various concentration trials and current
literature. There is a shift in Néel temperature (from <40 K to >50 K) from
previous literature.2,3
Higher Fe(II) concentrations result in increased initial growth of particle seeds.
This contributed to a greater variety in morphologies, but particles are smaller and
have less growth due to resources being used more quickly.
Lower Fe(II) concentrations result in fewer particle seeds. This contributed to less
variety of morphologies but larger particles, due to more growth since resources
are used slowly.
Future Work
Perform characterization on a siderite standard for comparison
Determine if drying effects are present
Conduct a time series to determine size dependency of the Néel temperature
Determine single domain size
Apply Mössbauer spectroscopy to determine any presence of Fe(III)
Perform synthesis with different reducing agents
Acknowledgements This work was supported by:
1) Frederichs, T., Von Dobeneck, T., Bleil, U., & Dekkers, M. J. (2003). Towards the identification of siderite, rhodochrosite, and vivianite in sediments by their low-temperature magnetic properties. Physics and Chemistry of the Earth, Parts A/B/C, 28(16), 669-679.
2) Pan, Y., Zhu, R., Liu, Q., Jackson, M. (2002). Low-temperature magnetic behavior related to thermal alteration of siderite. Geophys. Res. Lett, 29(23), 2087-2090.
3) Roh, Y., Zhang, C. L., Vali, H., Lauf, R. J., Zhou, J., & Phelps, T. J. (2003). Biogeochemical and environmental factors in Fe biomineralization: magnetite and siderite formation. Clays and Clay Minerals, 51(1), 83-95.
4) Qu, X. F., Yao, Q. Z., & Zhou, G. T. (2011). Synthesis of siderite microspheres and their transformation to magnetite microspheres. European Journal of Mineralogy, 23(5),759-770.
5) Romanek, C. S., Jiménez-López, C., Navarro, A. R., Sánchez-Román, M., Sahai, N., & Coleman, M. (2009). Inorganic synthesis of Fe–Ca–Mg carbonates at low temperature. Geochimica et Cosmochimica Acta, 73(18), 5361-5376.
6) Mozley, P. S., & Burns, S. J. (1993). Oxygen and carbon isotopic composition of marine carbonate concretions; an overview. Journal of Sedimentary Research, 63(1), 73-83.
Introduction
Siderite is an iron(II) carbonate (FeCO3) mineral commonly found in a range of
natural environments, including anaerobic aqueous ecosystems, systems containing
biomineralization and extraterrestrial formations.1-5
Siderite can be identified by a characteristic magnetic transition at low
temperatures below 40 K.1,2 It is important to be able to detect siderite through low
temperature rock magnetic analysis due to its ability to undergo phase transformation
to magnetite under certain conditions.2 It can also complicate carbon and oxygen
isotopic analyses in natural rock samples.6 Additionally, it may greatly assist in the
identification of biomineralization processes and paleoclimates.4
The goal of this project was to synthesize and characterize siderite particles of
varying morphologies and grain sizes. Using X-ray diffraction (XRD), scanning
electron microscopy (SEM), and Magnetic Properties Measurement System (MPMS)
analyses, we aim to determine trends between particle morphology, grain size, and
rock magnetic properties.
Experimental
The following synthetic procedure4 was completed at varying initial Fe(II)
concentrations: 0.033 M, 0.067 M, and 0.10 M.
One solution of 0.2 M sodium carbonate (Na2CO3) was combined with a solution
containing 0.2 M ascorbic acid and varying concentrations of ferrous sulfate
(FeSO4) in an autoclave with a total volume of 60 mL.
Particle suspension was aged for 4 hours at 130 °C. Once removed from oven,
suspension was cooled overnight to room temperature.
The suspension was then purified using dialysis until particles settled from
solution.
20 30 40 50 60 70 80
Inte
nsi
ty
2 Theta
Siderite
Siderite PDF
Ferrihydrite PDF
20 30 40 50 60 70 80
Inte
nsi
ty
2 Theta
Siderite
Siderite PDF
20 30 40 50 60 70 80
Inte
nsi
ty
2 Theta
Siderite
Siderite PDF
20 30 40 50 60 70 80
Inte
nsi
ty
2 Theta
Siderite
Siderite PDF
0
2
4
6
8
10
12
14
0 50 100 150 200 250 300
M (
10
-3A
m2/k
g)
Temperature (K)
FC
ZFC
0
5
10
15
20
0 50 100 150 200 250 300
M (
10
-6A
m2/k
g)
Temperature (K)
Cooling
Warming
0.15
0.25
0.35
0.45
0.55
0.65
0 50 100 150 200 250 300
M (
Am
2/k
g)
Temperature (K)
0
0.1
0.2
0.3
0.4
0.5
0.6
0 50 100 150 200 250 300
M (
Am
2/k
g)
Temperature (K)
0
1
2
3
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6
0 50 100 150 200 250 300
M (
10
-3A
m2/k
g)
Temperature (K)
FC
ZFC
0
5
10
15
20
25
30
35
40
45
0 50 100 150 200 250 300
M (
10
-6A
m2/k
g)
Temperature (K)
Cooling
Warming
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 50 100 150 200 250 300
M (
Am
2/k
g)
Temperature (K)
0
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0 50 100 150 200 250 300
M (
10
-3A
m2/k
g)
Temperature (K)
FC
ZFC
0
5
10
15
20
25
30
35
0 50 100 150 200 250 300
M (
10
-6A
m2/k
g)
Temperature (K)
Cooling
Warming
0
0.1
0.2
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0.4
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M (
Am
2/k
g)
Temperature (K)
~59 K
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0 50 100 150 200 250 300
M (
10
-3A
m2/k
g)
Temperature (K)
FC
ZFC
0
2
4
6
8
10
12
14
16
18
0 50 100 150 200 250 300
M (
10
-6A
m2/k
g)
Temperature (K)
Cooling
Warming
0.0
67 M
at
90 °
C
0.0
33 M
at
130 °
C
0.0
67 M
at
130 °
C
0.1
0 M
at
130 °
C
Parts of this work were carried out in the Characterization
Facility, University of Minnesota, which receives partial
support from NSF through the MRSEC program.
Undergraduate Research Opportunity Program
Institute for Rock Magnetism
National Science Foundation
References
SEM XRD Saturation Magnetization Field Cooled – Zero Field Cooled
Remanence Room Temperature Remanence
Figure 1: Analysis of siderite particles at various temperatures and initial Fe(II) concentrations. (left to right) Results of SEM, XRD, saturation magnetization, field cooled and zero-field cooled remanence and room temperature remanence. (top to
bottom) Concentration and temperature series including 0.067 M Fe(II) at 90 °C, 0.033 M Fe(II) at 130 °C, 0.067 M Fe(II) at 130 °C and 0.10 M Fe(II) at 130 °C.
~54 K
~57 K
~54 K
~60 K
~59 K
~60 K
~62 K
