Manganese valence imaging in Mn minerals at the nanoscale using STEM-EELS

Loomer, Diana B.; Al, Tom A.; Weaver, Louise; Cogswell, Steven

doi:10.2138/am.2007.2252

Cited by 55 publications

(52 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1c, where we plot Mn and Cu L 2,3 EELS spectra across the interface. The spectra show a progressive decrease of Cu and Mn valence, manifested in a change of the L 3 to L 2 ratio, in the layers located at the interface, suggesting a transfer of electrons from the bulk manganite film to the manganite and cuprate interfacial layers [17][18][19] . To quantify the effect, in Fig.…”

Section: Samplementioning

confidence: 97%

Ubiquitous long-range antiferromagnetic coupling across the interface between superconducting and ferromagnetic oxides

et al. 2014

View full text Add to dashboard Cite

The so-called proximity effect is the manifestation, across an interface, of the systematic competition between magnetic order and superconductivity. This phenomenon has been well documented and understood for conventional superconductors coupled with metallic ferromagnets; however it is still less known for oxide materials, where much higher critical temperatures are offered by copper oxide-based superconductors. Here we show that, even in the absence of direct Cu-O-Mn covalent bonding, the interfacial CuO 2 planes of superconducting La 1.85 Sr 0.15 CuO 4 thin films develop weak ferromagnetism associated to the charge transfer of spin-polarised electrons from the La 0.66 Sr 0.33 MnO 3 ferromagnet. Theoretical modelling confirms that this effect is general to all cuprate/manganite heterostructures and the presence of direct bonding only affects the strength of the coupling. The DzyaloshinskiiMoriya interaction, also at the origin of the weak ferromagnetism of bulk cuprates, propagates the magnetisation from the interface CuO 2 planes into the superconductor, eventually depressing its critical temperature.

show abstract

Section: Samplementioning

confidence: 97%

Ubiquitous long-range antiferromagnetic coupling across the interface between superconducting and ferromagnetic oxides

et al. 2014

View full text Add to dashboard Cite

show abstract

“…This reveals that the expected discharge-state valences 34 of Mn 4+ and Co 3+ are actually more reduced at the surface. 35,36 This Figure 9. change in the layered structure and valence indicates the formation of a rock-salt-structured phase in the surface region.…”

Section: Structure Of Thementioning

confidence: 94%

Surface Structure and High-Voltage Charge/Discharge Characteristics of Al-Oxide Coated LiNi_1/3Co_1/3Mn_1/3O₂Cathodes

Yano

Aoyama

Shikano

et al. 2015

J. Electrochem. Soc.

View full text Add to dashboard Cite

A sol-gel method was used to fabricate Al-oxide coated LiNi 1/3 Co 1/3 Mn 1/3 O 2 cathodes and their surface structure and high-voltage charge/discharge characteristics were evaluated with a view to their potential use in Li-ion batteries. Scanning transmission electron microscopy (STEM) revealed that a solid solution of LiAlO 2 -LiNi 1/3 Co 1/3 Mn 1/3 O 2 is uniformly formed to a depth of several nanometers from the surface of Al-oxide coated LiNi 1/3 Co 1/3 Mn 1/3 O 2 . Furthermore, the discharge capacity and average discharge voltage of Al-oxide coated LiNi 1/3 Co 1/3 Mn 1/3 O 2 is equal to or higher than uncoated LiNi 1/3 Co 1/3 Mn 1/3 O 2 at a charge voltage of 4.5 to 4.9 V. It was also found that the Al-oxide coating significantly improves the cycle performance at a charge voltage of 4.5 to 4.7 V. A substantial fade in capacity observed during the cycling of bare LiNi 1/3 Co 1/3 Mn 1/3 O 2 is attributed to an increase in polarization due to an increased charge transfer resistance (R ct ), which is indicative of degradation of the interface between the electrode and electrolyte. However, this increase in polarization and R ct is effectively suppressed in the Al-oxide coated LiNi 1/3 Co 1/3 Mn 1/3 O 2 . This can be explained by an inhibition of the formation of a rock-salt-structured phase in the surface region of bare LiNi 1/3 Co 1/3 Mn 1/3 O 2 during cycling, as confirmed by STEM and electron energy loss spectrometry.

show abstract

“…15) This is unfortunate since many environmentally important phases are rich in Mn(IV). Zhang et al (2010) assessed methods for determination of Mn(III)-Mn(IV) mixtures, and like Loomer et al (2007), used an internal standard but in the form of Ti metal. This allowed for the examination of the O K edge without contamination of O from TiO 2 .…”

Section: Quantification Of Valence By L 23 -Elnesmentioning

confidence: 99%

Analytical Transmission Electron Microscopy

Brydson

Brown

Benning

et al. 2014

Reviews in Mineralogy and Geochemistry

View full text Add to dashboard Cite

Manganese valence imaging in Mn minerals at the nanoscale using STEM-EELS

Cited by 55 publications

References 32 publications

Ubiquitous long-range antiferromagnetic coupling across the interface between superconducting and ferromagnetic oxides

Ubiquitous long-range antiferromagnetic coupling across the interface between superconducting and ferromagnetic oxides

Surface Structure and High-Voltage Charge/Discharge Characteristics of Al-Oxide Coated LiNi_1/3Co_1/3Mn_1/3O₂Cathodes

Analytical Transmission Electron Microscopy

Contact Info

Product

Resources

About

Manganese valence imaging in Mn minerals at the nanoscale using STEM-EELS

Cited by 55 publications

References 32 publications

Ubiquitous long-range antiferromagnetic coupling across the interface between superconducting and ferromagnetic oxides

Ubiquitous long-range antiferromagnetic coupling across the interface between superconducting and ferromagnetic oxides

Surface Structure and High-Voltage Charge/Discharge Characteristics of Al-Oxide Coated LiNi1/3Co1/3Mn1/3O2Cathodes

Analytical Transmission Electron Microscopy

Contact Info

Product

Resources

About

Surface Structure and High-Voltage Charge/Discharge Characteristics of Al-Oxide Coated LiNi_1/3Co_1/3Mn_1/3O₂Cathodes