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Esther S. Takeuchi - One of the best experts on this subject based on the ideXlab platform.
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Temporally and Spatially Resolved Visualization of Electrochemical Conversion: Monitoring Phase Distribution During Lithiation of Magnetite (fe3o4) Electrodes
ACS Applied Energy Materials, 2019Co-Authors: Andrea M. Bruck, David C. Bock, Kenneth J. Takeuchi, Esther S. Takeuchi, Nicholas W. Brady, Christianna N. Lininger, Alexander B. Brady, Killian R. Tallman, Calvin D. Quilty, Alan C. WestAbstract:Fundamental understanding of transport properties across multiple size regimes is critical for the rational design of electrodes with conversion materials. While recent studies have effectively interrogated mass transport in the conversion material Magnetite (fe3o4), a remaining challenge is to understand how electron and ion transport progress in a thick electrode. To provide insight, this study performs characterization of Li/fe3o4 electrochemical cells both in situ and operando using synchrotron energy dispersive energy diffraction (EDXRD). In situ EDXRD measurements performed after 14 days of open circuit voltage recovery exhibit phase homogeneity with no observable reaction front for rocksalt formation. Operando EDXRD results clearly reveal that the insertion and conversion reactions associated with lithiation of fe3o4 initiate at the Li anode interface and propagate as a reaction front through the electrode. The variation between the in situ and operando measurements necessitated the development of ...
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Isothermal Microcalorimetry: Insight into the Impact of Crystallite Size and Agglomeration on the Lithiation of Magnetite, fe3o4.
ACS applied materials & interfaces, 2019Co-Authors: Matthew M. Huie, David C. Bock, Kenneth J. Takeuchi, Esther S. Takeuchi, Lei Wang, Andrea M. Bruck, Killian R. Tallman, Lisa M. Housel, Juergen Thieme, Amy C. MarschilokAbstract:Magnetite, fe3o4, holds significant interest as a Li-ion anode material because of its high theoretical capacity (926 mAh/g) associated with multiple electron transfers per cation center. Notably, both crystallite size and agglomeration influence ion transport. This report probes the effects of crystallite size (12 and 29 nm) and agglomeration on the reactions involved with the formation of the surface electrolyte interphase on fe3o4. Isothermal microcalorimetry (IMC) was used to determine the parasitic heat evolved during lithiation by considering the total heat measured, cell polarization, and entropic contributions. Interestingly, the 29 nm fe3o4-based electrodes produced more parasitic heat than the 12 nm samples (1346 vs 1155 J/g). This observation was explored using scanning electron microscopy (SEM) and X-ray fluorescence (XRF) mapping in conjunction with spatially resolved X-ray absorption spectroscopy (XAS). SEM imaging of the electrodes revealed more agglomerates for the 12 nm material, affirmed...
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Investigation of Solid Electrolyte Interphase Layer Formation and Electrochemical Reversibility of Magnetite, fe3o4, Electrodes: A Combined X-ray Absorption Spectroscopy and X-ray Photoelectron Spectroscopy Study
The Journal of Physical Chemistry C, 2018Co-Authors: David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Gordon H. Waller, Azzam N. Mansour, Esther S. TakeuchiAbstract:Magnetite (fe3o4) is a promising electrode material for the next generation of Li-ion batteries with multiple electron transfers per metal center and a theoretical capacity of 924 mA h/g. However, multiple phase conversions during (de)lithiation of fe3o4 and formation of a solid electrolyte interphase (SEI) contribute to capacity fade. In this study, X-ray absorption spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to determine the surface chemistry, redox chemistry, and the impact on the electrochemical reversibility in the presence and absence of fluoroethylene carbonate (FEC) solvent. With FEC, improved capacity retention and enhanced reversibility are observed. In contrast, electrodes cycled with no FEC exhibit decreased reversibility where the active material remains as reduced Fe0. XPS results reveal LiF and lower quantities of oxygen-containing species, especially carbonates at the electrode surface tested in FEC. The improvement in electrochemical reversibility with FEC is attribu...
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Lithiation of Magnetite (fe3o4): Analysis Using Isothermal Microcalorimetry and Operando X-ray Absorption Spectroscopy
The Journal of Physical Chemistry C, 2018Co-Authors: Matthew M. Huie, David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Lei Wang, Esther S. TakeuchiAbstract:Conversion electrodes, such as Magnetite (fe3o4), offer high theoretical capacities (>900 mAh/g) because of multiple electron transfer per metal center. Capacity retention for conversion electrodes has been a challenge in part because of the formation of an insulating surface electrolyte interphase (SEI). This study provides the first detailed analysis of the lithiation of fe3o4 using isothermal microcalorimetry (IMC). The measured heat flow was compared with heat contributions predicted from heats of formation for the Faradaic reaction, cell polarization, and entropic contributions. The total measured energy output of the cell (7260 J/g fe3o4) exceeded the heat of reaction predicted for full lithiation of fe3o4 (5508 J/g). During initial lithiation (3.0–0.86 V), the heat flow was successfully modeled using polarization and entropic contributions. Heat flow at lower voltage (0.86–0.03 V) exceeded the predicted values for iron oxide reduction, consistent with heat generation attributable to electrolyte dec...
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Deliberate modification of the solid electrolyte interphase (SEI) during lithiation of Magnetite, fe3o4: impact on electrochemistry
Chemical communications (Cambridge England), 2017Co-Authors: David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Esther S. TakeuchiAbstract:Magnetite is a conversion anode material displaying multi-electron transfer during lithiation and delithiation. The solid electrolyte interphase (SEI) on Magnetite, fe3o4, electrodes for lithium ion batteries was deliberately modified through the use of fluoroethylene carbonate (FEC) electrolyte additive, improving both capacity retention and rate capability. Analysis showed reduction of FEC at higher voltage compared to non-fluorinated solvents with formation of a modified lithium flouride containing electrode surface.
David C. Bock - One of the best experts on this subject based on the ideXlab platform.
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Temporally and Spatially Resolved Visualization of Electrochemical Conversion: Monitoring Phase Distribution During Lithiation of Magnetite (fe3o4) Electrodes
ACS Applied Energy Materials, 2019Co-Authors: Andrea M. Bruck, David C. Bock, Kenneth J. Takeuchi, Esther S. Takeuchi, Nicholas W. Brady, Christianna N. Lininger, Alexander B. Brady, Killian R. Tallman, Calvin D. Quilty, Alan C. WestAbstract:Fundamental understanding of transport properties across multiple size regimes is critical for the rational design of electrodes with conversion materials. While recent studies have effectively interrogated mass transport in the conversion material Magnetite (fe3o4), a remaining challenge is to understand how electron and ion transport progress in a thick electrode. To provide insight, this study performs characterization of Li/fe3o4 electrochemical cells both in situ and operando using synchrotron energy dispersive energy diffraction (EDXRD). In situ EDXRD measurements performed after 14 days of open circuit voltage recovery exhibit phase homogeneity with no observable reaction front for rocksalt formation. Operando EDXRD results clearly reveal that the insertion and conversion reactions associated with lithiation of fe3o4 initiate at the Li anode interface and propagate as a reaction front through the electrode. The variation between the in situ and operando measurements necessitated the development of ...
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Isothermal Microcalorimetry: Insight into the Impact of Crystallite Size and Agglomeration on the Lithiation of Magnetite, fe3o4.
ACS applied materials & interfaces, 2019Co-Authors: Matthew M. Huie, David C. Bock, Kenneth J. Takeuchi, Esther S. Takeuchi, Lei Wang, Andrea M. Bruck, Killian R. Tallman, Lisa M. Housel, Juergen Thieme, Amy C. MarschilokAbstract:Magnetite, fe3o4, holds significant interest as a Li-ion anode material because of its high theoretical capacity (926 mAh/g) associated with multiple electron transfers per cation center. Notably, both crystallite size and agglomeration influence ion transport. This report probes the effects of crystallite size (12 and 29 nm) and agglomeration on the reactions involved with the formation of the surface electrolyte interphase on fe3o4. Isothermal microcalorimetry (IMC) was used to determine the parasitic heat evolved during lithiation by considering the total heat measured, cell polarization, and entropic contributions. Interestingly, the 29 nm fe3o4-based electrodes produced more parasitic heat than the 12 nm samples (1346 vs 1155 J/g). This observation was explored using scanning electron microscopy (SEM) and X-ray fluorescence (XRF) mapping in conjunction with spatially resolved X-ray absorption spectroscopy (XAS). SEM imaging of the electrodes revealed more agglomerates for the 12 nm material, affirmed...
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Investigation of Solid Electrolyte Interphase Layer Formation and Electrochemical Reversibility of Magnetite, fe3o4, Electrodes: A Combined X-ray Absorption Spectroscopy and X-ray Photoelectron Spectroscopy Study
The Journal of Physical Chemistry C, 2018Co-Authors: David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Gordon H. Waller, Azzam N. Mansour, Esther S. TakeuchiAbstract:Magnetite (fe3o4) is a promising electrode material for the next generation of Li-ion batteries with multiple electron transfers per metal center and a theoretical capacity of 924 mA h/g. However, multiple phase conversions during (de)lithiation of fe3o4 and formation of a solid electrolyte interphase (SEI) contribute to capacity fade. In this study, X-ray absorption spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to determine the surface chemistry, redox chemistry, and the impact on the electrochemical reversibility in the presence and absence of fluoroethylene carbonate (FEC) solvent. With FEC, improved capacity retention and enhanced reversibility are observed. In contrast, electrodes cycled with no FEC exhibit decreased reversibility where the active material remains as reduced Fe0. XPS results reveal LiF and lower quantities of oxygen-containing species, especially carbonates at the electrode surface tested in FEC. The improvement in electrochemical reversibility with FEC is attribu...
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Lithiation of Magnetite (fe3o4): Analysis Using Isothermal Microcalorimetry and Operando X-ray Absorption Spectroscopy
The Journal of Physical Chemistry C, 2018Co-Authors: Matthew M. Huie, David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Lei Wang, Esther S. TakeuchiAbstract:Conversion electrodes, such as Magnetite (fe3o4), offer high theoretical capacities (>900 mAh/g) because of multiple electron transfer per metal center. Capacity retention for conversion electrodes has been a challenge in part because of the formation of an insulating surface electrolyte interphase (SEI). This study provides the first detailed analysis of the lithiation of fe3o4 using isothermal microcalorimetry (IMC). The measured heat flow was compared with heat contributions predicted from heats of formation for the Faradaic reaction, cell polarization, and entropic contributions. The total measured energy output of the cell (7260 J/g fe3o4) exceeded the heat of reaction predicted for full lithiation of fe3o4 (5508 J/g). During initial lithiation (3.0–0.86 V), the heat flow was successfully modeled using polarization and entropic contributions. Heat flow at lower voltage (0.86–0.03 V) exceeded the predicted values for iron oxide reduction, consistent with heat generation attributable to electrolyte dec...
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Deliberate modification of the solid electrolyte interphase (SEI) during lithiation of Magnetite, fe3o4: impact on electrochemistry
Chemical communications (Cambridge England), 2017Co-Authors: David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Esther S. TakeuchiAbstract:Magnetite is a conversion anode material displaying multi-electron transfer during lithiation and delithiation. The solid electrolyte interphase (SEI) on Magnetite, fe3o4, electrodes for lithium ion batteries was deliberately modified through the use of fluoroethylene carbonate (FEC) electrolyte additive, improving both capacity retention and rate capability. Analysis showed reduction of FEC at higher voltage compared to non-fluorinated solvents with formation of a modified lithium flouride containing electrode surface.
Amy C. Marschilok - One of the best experts on this subject based on the ideXlab platform.
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Isothermal Microcalorimetry: Insight into the Impact of Crystallite Size and Agglomeration on the Lithiation of Magnetite, fe3o4.
ACS applied materials & interfaces, 2019Co-Authors: Matthew M. Huie, David C. Bock, Kenneth J. Takeuchi, Esther S. Takeuchi, Lei Wang, Andrea M. Bruck, Killian R. Tallman, Lisa M. Housel, Juergen Thieme, Amy C. MarschilokAbstract:Magnetite, fe3o4, holds significant interest as a Li-ion anode material because of its high theoretical capacity (926 mAh/g) associated with multiple electron transfers per cation center. Notably, both crystallite size and agglomeration influence ion transport. This report probes the effects of crystallite size (12 and 29 nm) and agglomeration on the reactions involved with the formation of the surface electrolyte interphase on fe3o4. Isothermal microcalorimetry (IMC) was used to determine the parasitic heat evolved during lithiation by considering the total heat measured, cell polarization, and entropic contributions. Interestingly, the 29 nm fe3o4-based electrodes produced more parasitic heat than the 12 nm samples (1346 vs 1155 J/g). This observation was explored using scanning electron microscopy (SEM) and X-ray fluorescence (XRF) mapping in conjunction with spatially resolved X-ray absorption spectroscopy (XAS). SEM imaging of the electrodes revealed more agglomerates for the 12 nm material, affirmed...
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Investigation of Solid Electrolyte Interphase Layer Formation and Electrochemical Reversibility of Magnetite, fe3o4, Electrodes: A Combined X-ray Absorption Spectroscopy and X-ray Photoelectron Spectroscopy Study
The Journal of Physical Chemistry C, 2018Co-Authors: David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Gordon H. Waller, Azzam N. Mansour, Esther S. TakeuchiAbstract:Magnetite (fe3o4) is a promising electrode material for the next generation of Li-ion batteries with multiple electron transfers per metal center and a theoretical capacity of 924 mA h/g. However, multiple phase conversions during (de)lithiation of fe3o4 and formation of a solid electrolyte interphase (SEI) contribute to capacity fade. In this study, X-ray absorption spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to determine the surface chemistry, redox chemistry, and the impact on the electrochemical reversibility in the presence and absence of fluoroethylene carbonate (FEC) solvent. With FEC, improved capacity retention and enhanced reversibility are observed. In contrast, electrodes cycled with no FEC exhibit decreased reversibility where the active material remains as reduced Fe0. XPS results reveal LiF and lower quantities of oxygen-containing species, especially carbonates at the electrode surface tested in FEC. The improvement in electrochemical reversibility with FEC is attribu...
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Lithiation of Magnetite (fe3o4): Analysis Using Isothermal Microcalorimetry and Operando X-ray Absorption Spectroscopy
The Journal of Physical Chemistry C, 2018Co-Authors: Matthew M. Huie, David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Lei Wang, Esther S. TakeuchiAbstract:Conversion electrodes, such as Magnetite (fe3o4), offer high theoretical capacities (>900 mAh/g) because of multiple electron transfer per metal center. Capacity retention for conversion electrodes has been a challenge in part because of the formation of an insulating surface electrolyte interphase (SEI). This study provides the first detailed analysis of the lithiation of fe3o4 using isothermal microcalorimetry (IMC). The measured heat flow was compared with heat contributions predicted from heats of formation for the Faradaic reaction, cell polarization, and entropic contributions. The total measured energy output of the cell (7260 J/g fe3o4) exceeded the heat of reaction predicted for full lithiation of fe3o4 (5508 J/g). During initial lithiation (3.0–0.86 V), the heat flow was successfully modeled using polarization and entropic contributions. Heat flow at lower voltage (0.86–0.03 V) exceeded the predicted values for iron oxide reduction, consistent with heat generation attributable to electrolyte dec...
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Deliberate modification of the solid electrolyte interphase (SEI) during lithiation of Magnetite, fe3o4: impact on electrochemistry
Chemical communications (Cambridge England), 2017Co-Authors: David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Esther S. TakeuchiAbstract:Magnetite is a conversion anode material displaying multi-electron transfer during lithiation and delithiation. The solid electrolyte interphase (SEI) on Magnetite, fe3o4, electrodes for lithium ion batteries was deliberately modified through the use of fluoroethylene carbonate (FEC) electrolyte additive, improving both capacity retention and rate capability. Analysis showed reduction of FEC at higher voltage compared to non-fluorinated solvents with formation of a modified lithium flouride containing electrode surface.
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2d cross sectional analysis and associated electrochemistry of composite electrodes containing dispersed agglomerates of nanocrystalline Magnetite fe3o4
ACS Applied Materials & Interfaces, 2015Co-Authors: David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Kevin Kirshenbaum, Jiajun Wang, Wei Zhang, Feng Wang, Jun Wang, Esther S. TakeuchiAbstract:When electroactive nanomaterials are fully incorporated into an electrode structure, characterization of the crystallite sizes, agglomerate sizes, and dispersion of the electroactive materials can lend insight into the complex electrochemistry associated with composite electrodes. In this study, composite Magnetite electrodes were sectioned using ultramicrotome techniques, which facilitated the direct observation of crystallites and agglomerates of Magnetite (fe3o4) as well as their dispersal patterns in large representative sections of electrode, via 2D cross sectional analysis by Transmission Electron Microscopy (TEM). Further, the electrochemistry of these electrodes were recorded, and Transmission X-ray Microscopy (TXM) was used to determine the distribution of oxidation states of the reduced Magnetite. Unexpectedly, while two crystallite sizes of Magnetite were employed in the production of the composite electrodes, the Magnetite agglomerate sizes and degrees of dispersion in the two composite electr...
Kenneth J. Takeuchi - One of the best experts on this subject based on the ideXlab platform.
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Temporally and Spatially Resolved Visualization of Electrochemical Conversion: Monitoring Phase Distribution During Lithiation of Magnetite (fe3o4) Electrodes
ACS Applied Energy Materials, 2019Co-Authors: Andrea M. Bruck, David C. Bock, Kenneth J. Takeuchi, Esther S. Takeuchi, Nicholas W. Brady, Christianna N. Lininger, Alexander B. Brady, Killian R. Tallman, Calvin D. Quilty, Alan C. WestAbstract:Fundamental understanding of transport properties across multiple size regimes is critical for the rational design of electrodes with conversion materials. While recent studies have effectively interrogated mass transport in the conversion material Magnetite (fe3o4), a remaining challenge is to understand how electron and ion transport progress in a thick electrode. To provide insight, this study performs characterization of Li/fe3o4 electrochemical cells both in situ and operando using synchrotron energy dispersive energy diffraction (EDXRD). In situ EDXRD measurements performed after 14 days of open circuit voltage recovery exhibit phase homogeneity with no observable reaction front for rocksalt formation. Operando EDXRD results clearly reveal that the insertion and conversion reactions associated with lithiation of fe3o4 initiate at the Li anode interface and propagate as a reaction front through the electrode. The variation between the in situ and operando measurements necessitated the development of ...
-
Isothermal Microcalorimetry: Insight into the Impact of Crystallite Size and Agglomeration on the Lithiation of Magnetite, fe3o4.
ACS applied materials & interfaces, 2019Co-Authors: Matthew M. Huie, David C. Bock, Kenneth J. Takeuchi, Esther S. Takeuchi, Lei Wang, Andrea M. Bruck, Killian R. Tallman, Lisa M. Housel, Juergen Thieme, Amy C. MarschilokAbstract:Magnetite, fe3o4, holds significant interest as a Li-ion anode material because of its high theoretical capacity (926 mAh/g) associated with multiple electron transfers per cation center. Notably, both crystallite size and agglomeration influence ion transport. This report probes the effects of crystallite size (12 and 29 nm) and agglomeration on the reactions involved with the formation of the surface electrolyte interphase on fe3o4. Isothermal microcalorimetry (IMC) was used to determine the parasitic heat evolved during lithiation by considering the total heat measured, cell polarization, and entropic contributions. Interestingly, the 29 nm fe3o4-based electrodes produced more parasitic heat than the 12 nm samples (1346 vs 1155 J/g). This observation was explored using scanning electron microscopy (SEM) and X-ray fluorescence (XRF) mapping in conjunction with spatially resolved X-ray absorption spectroscopy (XAS). SEM imaging of the electrodes revealed more agglomerates for the 12 nm material, affirmed...
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Investigation of Solid Electrolyte Interphase Layer Formation and Electrochemical Reversibility of Magnetite, fe3o4, Electrodes: A Combined X-ray Absorption Spectroscopy and X-ray Photoelectron Spectroscopy Study
The Journal of Physical Chemistry C, 2018Co-Authors: David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Gordon H. Waller, Azzam N. Mansour, Esther S. TakeuchiAbstract:Magnetite (fe3o4) is a promising electrode material for the next generation of Li-ion batteries with multiple electron transfers per metal center and a theoretical capacity of 924 mA h/g. However, multiple phase conversions during (de)lithiation of fe3o4 and formation of a solid electrolyte interphase (SEI) contribute to capacity fade. In this study, X-ray absorption spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to determine the surface chemistry, redox chemistry, and the impact on the electrochemical reversibility in the presence and absence of fluoroethylene carbonate (FEC) solvent. With FEC, improved capacity retention and enhanced reversibility are observed. In contrast, electrodes cycled with no FEC exhibit decreased reversibility where the active material remains as reduced Fe0. XPS results reveal LiF and lower quantities of oxygen-containing species, especially carbonates at the electrode surface tested in FEC. The improvement in electrochemical reversibility with FEC is attribu...
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Lithiation of Magnetite (fe3o4): Analysis Using Isothermal Microcalorimetry and Operando X-ray Absorption Spectroscopy
The Journal of Physical Chemistry C, 2018Co-Authors: Matthew M. Huie, David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Lei Wang, Esther S. TakeuchiAbstract:Conversion electrodes, such as Magnetite (fe3o4), offer high theoretical capacities (>900 mAh/g) because of multiple electron transfer per metal center. Capacity retention for conversion electrodes has been a challenge in part because of the formation of an insulating surface electrolyte interphase (SEI). This study provides the first detailed analysis of the lithiation of fe3o4 using isothermal microcalorimetry (IMC). The measured heat flow was compared with heat contributions predicted from heats of formation for the Faradaic reaction, cell polarization, and entropic contributions. The total measured energy output of the cell (7260 J/g fe3o4) exceeded the heat of reaction predicted for full lithiation of fe3o4 (5508 J/g). During initial lithiation (3.0–0.86 V), the heat flow was successfully modeled using polarization and entropic contributions. Heat flow at lower voltage (0.86–0.03 V) exceeded the predicted values for iron oxide reduction, consistent with heat generation attributable to electrolyte dec...
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Deliberate modification of the solid electrolyte interphase (SEI) during lithiation of Magnetite, fe3o4: impact on electrochemistry
Chemical communications (Cambridge England), 2017Co-Authors: David C. Bock, Amy C. Marschilok, Kenneth J. Takeuchi, Esther S. TakeuchiAbstract:Magnetite is a conversion anode material displaying multi-electron transfer during lithiation and delithiation. The solid electrolyte interphase (SEI) on Magnetite, fe3o4, electrodes for lithium ion batteries was deliberately modified through the use of fluoroethylene carbonate (FEC) electrolyte additive, improving both capacity retention and rate capability. Analysis showed reduction of FEC at higher voltage compared to non-fluorinated solvents with formation of a modified lithium flouride containing electrode surface.
Nujiang Tang - One of the best experts on this subject based on the ideXlab platform.
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nanostructured Magnetite fe3o4 thin films prepared by sol gel method
Journal of Magnetism and Magnetic Materials, 2004Co-Authors: Nujiang Tang, Wei Zhong, H.y. Jiang, W. LiuAbstract:Abstract Nanostructured Magnetite (fe3o4) thin films have been prepared by a sol–gel method heated at 300°C. The film with a black appearance is homogeneous without cracks by adding N, N-dimethyl formamide (DMF) as drying chemical control agent (DCCA). The root mean square roughness of the thin film is only 2 nm, and the nanograins show a narrow size distribution with an average size of 12.5 nm. The magneto-optical Kerr effect (MOKE), measured in the applied field range from 0 to 1.9 T, reveals that the film exhibits superparamagnetism.
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Nanostructured Magnetite (fe3o4) thin films prepared by sol–gel method
Journal of Magnetism and Magnetic Materials, 2004Co-Authors: Nujiang Tang, Wei Zhong, H.y. Jiang, W. LiuAbstract:Abstract Nanostructured Magnetite (fe3o4) thin films have been prepared by a sol–gel method heated at 300°C. The film with a black appearance is homogeneous without cracks by adding N, N-dimethyl formamide (DMF) as drying chemical control agent (DCCA). The root mean square roughness of the thin film is only 2 nm, and the nanograins show a narrow size distribution with an average size of 12.5 nm. The magneto-optical Kerr effect (MOKE), measured in the applied field range from 0 to 1.9 T, reveals that the film exhibits superparamagnetism.