Related Experiment Video
Updated: May 15, 2026
11:50
Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions
Published on: June 13, 2015
Li11Nd18Fe4O(39-δ) revisited
Peter D Battle1, Sian E Dutton, Fernande Grandjean
1Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK. peter.battle@chem.ox.ac.uk
Inorganic Chemistry
|January 4, 2013
Summary
This study reevaluates the crystal structure of iron-based oxides, comparing two proposed models. Findings suggest differences in iron cation site occupancy and propose one structure as a kinetic product and the other as thermodynamically preferred.
Area of Science:
- Solid-state chemistry
- Materials science
- Crystallography
Background:
- Two distinct crystal structures have been proposed for iron-based neodymium lithium oxides.
- Previous studies utilized diffraction and Mössbauer spectroscopy to elucidate these structures.
Purpose of the Study:
- To compare the proposed structures of Li(11)Nd(18)Fe(4)O(39-δ) and Nd(18)Li(8)Fe(5)O(39).
- To re-examine and reinterpret existing Mössbauer spectral data.
- To clarify the relationship between the two proposed oxide phases.
Main Methods:
- Reinterpretation of Mössbauer spectral data.
- Comparison of structural models derived from diffraction and spectroscopy.
- Analysis of iron cation site occupancy in space group Pm3n.
Main Results:
- Refined Mössbauer parameters differ significantly from previously published values.
- Iron cations occupy 2a, 8e, and 16i sites, contradicting neutron diffraction findings for one model.
- The structure proposed by Chen et al. (2012) is suggested to be the thermodynamically preferred product, while Dutton et al. (2008) prepared a kinetic product.
Conclusions:
- The reevaluation of spectral data challenges the proposed structure by Chen et al.
- Discrepancies in iron cation site occupancy highlight the importance of accurate structural determination.
- The findings suggest a kinetic versus thermodynamic control in the synthesis of these neodymium lithium iron oxides.
More Related Videos
Related Concept Videos
04:00Periodic Classification of the Elements
The periodic table arranges atoms based on increasing atomic number so that elements with the same chemical properties recur periodically. When their electron configurations are added to the table, a periodic recurrence of similar electron configurations in the outer shells of these elements is observed. Because they are in the outer shells of an atom, valence electrons play the most important role in chemical reactions. The outer electrons have the highest energy of the electrons in an atom...
02:58Properties of Transition Metals
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
03:02Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
03:26Electron Configuration of Multielectron Atoms
The alkali metal sodium (atomic number 11) has one more electron than the neon atom. This electron must go into the lowest-energy subshell available, the 3s orbital, giving a 1s22s22p63s1 configuration. The electrons occupying the outermost shell orbital(s) (highest value of n) are called valence electrons, and those occupying the inner shell orbitals are called core electrons. Since the core electron shells correspond to noble gas electron configurations, we can abbreviate electron...
01:16Other Nuclides: 31P, 19F, 15N NMR
Many organic, inorganic, and biological molecules contain spin-half nuclei such as nitrogen-15, fluorine-19, and phosphorus-31. As a result, NMR studies of these nuclei have found extensive applications in chemical and biological research.
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a high...
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a high...
02:46Electron Configurations
Electron configurations and orbital diagrams can be determined by applying the Aufbau principle (each added electron occupies the subshell of lowest energy available), Pauli exclusion principle (no two electrons can have the same set of four quantum numbers), and Hund’s rule of maximum multiplicity (whenever possible, electrons retain unpaired spins in degenerate orbitals).
The relative energies of the subshells determine the order in which atomic orbitals are filled (1s, 2s, 2p, 3s, 3p, 4s,...
The relative energies of the subshells determine the order in which atomic orbitals are filled (1s, 2s, 2p, 3s, 3p, 4s,...