Roles of transition metals interchanging with lithium in electrode materials

2015 ◽  
Vol 17 (21) ◽  
pp. 14064-14070 ◽  
Author(s):  
Tomoya Kawaguchi ◽  
Katsutoshi Fukuda ◽  
Kazuya Tokuda ◽  
Masashi Sakaida ◽  
Tetsu Ichitsubo ◽  
...  

Roles of antisite transition metals interchanging with Li atoms in electrode materials of layered rock-salt structure were site-selectively clarified using a newly developed powder diffraction anomalous fine structure.

1998 ◽  
Vol 5 (3) ◽  
pp. 1061-1063 ◽  
Author(s):  
H. Ofuchi ◽  
D. Kawamura ◽  
J. Tsuchiya ◽  
N. Matsubara ◽  
M. Tabuchi ◽  
...  

For understanding the luminescence of Er atoms in III–V semiconductors, OMVPE-grown InP doped with Er has been investigated by fluorescence EXAFS (extended X-ray absorption fine structure) in order to study the local structure around Er atoms. The local structures around the Er atoms doped in InP, with doping as dilute as 3 × 1012 Er atoms in a 1.5 mm × 1.0 mm spot, were successfully measured by fluorescence EXAFS. The EXAFS analysis revealed that the Er atoms doped in InP above 853 K (which showed low luminescence) formed the rock-salt-structure ErP, while the Er atoms doped in InP below 823 K (which showed high luminescence) substituted on the In site of InP. The dependence of the local structure on growth temperature was observed for the samples doped with 3 × 1012 atoms and 1.2 × 1013 atoms of Er.


2008 ◽  
Vol 104 (4) ◽  
pp. 043909 ◽  
Author(s):  
Mitsuharu Tabuchi ◽  
Kuniaki Tatsumi ◽  
Shotaro Morimoto ◽  
Saburo Nasu ◽  
Tadashi Saito ◽  
...  

Author(s):  
Qian Zhang ◽  
William Arnold ◽  
Zachary D. Hood ◽  
Yang Li ◽  
Rachel DeWees ◽  
...  

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
S. Shari ◽  
K.B. Tan ◽  
C.C. Khaw ◽  
Z. Zainal ◽  
O.J. Lee ◽  
...  

AbstractLithium tantalate solid solution, Li3+5xTa1−xO4 was prepared by conventional solid-state reaction at 925 °C for 48 h. The XRD analysis confirmed that these materials crystallized in a monoclinic symmetry, space group C2/C and Z = 8, which was similar to the reported International Crystal Database (ICDD), No. 98-006-7675. The host structure, β-Li3TaO4 had a rock-salt structure with a cationic order of Li+:Ta5+ = 3:1 over the octahedral sites. A rather narrow subsolidus solution range, i.e. Li3+5xTa1−xO4 (0 ⩽ x ⩽ 0.059) was determined and the formation mechanism was proposed as a replacement of Ta5+ by excessive Li+, i.e. Ta5+ ↔ 5Li+. Both Scherrer and Williamson-Hall (W-H) methods indicated the average crystallite sizes in the range of 31 nm to 51 nm. Two secondary phases, Li4TaO4:5 and LiTaO3 were observed at x = 0.070 and x = −0:013, respectively. These materials were moderate lithium ionic conductors with the highest conductivity of ~2.5 × 10−3 Ω 1 ˙cm−1 at x = 0, at 0 °C and 850 °C; the activation energies were found in the range of 0.63 eV to 0.68 eV.


2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
A. Alsaad

Direct supercell approach calculations of the magnetic exchange interactions in Mn-doped ScN was carried out in the local spin density approximation by using the muffin-tin-orbital Green's function method. We found that magnetic interactions are long range interactions and affected by the randomness, band gap corrections, and carrier concentrations. Using total energy minimization approach we found that the global energy minimum of MnN is obtained for zinc-blende structure. If the compound is compressed by 6%, the energy minimum corresponds to the rock-salt structure in disagreement with the experimentally observed tetragonal distorted rock-salt structure, known as -phase. An isostructural phase transition for alloys from MnN -phase to -ScN phase was found to occur at a hydrostatic pressure of 18 GPa. We predict above room temperature for Mn concentrations of about 10% in ScN : Mn system.


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