Local Lattice Distortion Caused by Short Range Charge Ordering in LiMn2O4

Cluster Variation Method (CVM) is a powerful statistical mechanics means to investigate phase equilibria of an alloy. The advantageous feature of the CVM stems from the fact that wide range of atomic correlations which play an important role at the phase transition is efficiently incorporated into the free energy formula. Hence, configurational fluctuation can be systematically studied through the calculations of correlation functions in the real space and short range order diffuse intensity spectrum in the k-space. However, one of the deficiencies of the conventional CVM is the fact that local lattice distortion (local atomic displacement) is not correctly dealt with. In order to improve such shortcomings, Continuous Displacement Cluster Variation Method (CDCVM) has been developed. In the CDCVM, local lattice distortion is mapped onto the configurational freedom of a multi-component alloy on a rigid (uniformly deformable) lattice. With CDCVM, the applicability of CVM is enlarged and the calculations of diffuse intensity spectrum originating from local lattice distortion can be performed.

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Doping Effect on the Charge Ordering in LuFe2O4

MRS Proceedings ◽

10.1557/proc-0966-t03-04 ◽

2006 ◽

Vol 966 ◽

Author(s):

Yoji Matsuo ◽

Satoshi Shinohara ◽

Shigeo Mori ◽

Yoichi Horibe ◽

Kenji Yoshii ◽

...

Keyword(s):

Lattice Distortion ◽

Magnetic Measurement ◽

Charge Ordering ◽

Local Lattice Distortion ◽

Modulated Structure ◽

Transmission Electron ◽

Short Range Ordering ◽

Local Lattice ◽

Lattice Images ◽

Average Size

ABSTRACTChange of the charge ordered (CO) structure by substituting Cu2+ for Fe2+ in LuFe2O4 was investigated by means of the transmission electron microscopy. The CO structure in LuFe2O4 is characterized by the modulated structure with the wave vector of q=1/3[1-13/2] and the average size of the CO domains can be estimated to be about 10-20nm. On the contrary, the Cu2+ substitution in LuFe2O4 destroyed the CO structure drastically and induced characteristic local lattice distortion, which gives rise to characteristic diffuse scattering in the reciprocal space. High-resolution lattice images revealed that there exist nano-scale clusters, which are characterized as the short-range ordering of the Fe3+ and Cu2+ ions on the triangular lattice. In addition, the magnetic measurement revealed that LuFeCuO4 exhibits an antiferromagnetic transition around 50K, which is lower than the Neel temperature of 250K in LuFe2O4.

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Short-range chemical order and local lattice distortion in a compositionally complex alloy

Acta Materialia ◽

10.1016/j.actamat.2020.04.034 ◽

2020 ◽

Vol 193 ◽

pp. 329-337 ◽

Cited By ~ 3

Author(s):

Andrea Fantin ◽

Giovanni Orazio Lepore ◽

Anna M. Manzoni ◽

Sergey Kasatikov ◽

Tobias Scherb ◽

...

Keyword(s):

Short Range ◽

Lattice Distortion ◽

Local Lattice Distortion ◽

Complex Alloy ◽

Chemical Order ◽

Local Lattice

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Element-resolved local lattice distortion in complex concentrated alloys: An observable signature of electronic effects

Acta Materialia ◽

10.1016/j.actamat.2021.117135 ◽

2021 ◽

pp. 117135

Author(s):

Hyun Seok Oh ◽

Khorgolkhuu Odbadrakh ◽

Yuji Ikeda ◽

Sai Mu ◽

Fritz Körmann ◽

...

Keyword(s):

Lattice Distortion ◽

Electronic Effects ◽

Local Lattice Distortion ◽

Local Lattice

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Ab initio study of local lattice distortion of hexagonal closed-packed high-entropy (Mo0.25Nb0.25Ta0.25V0.25) (Al0.5Si0.5)2 and the influence on thermodynamic property

Journal of Solid State Chemistry ◽

10.1016/j.jssc.2021.122469 ◽

2021 ◽

pp. 122469

Author(s):

Xiao-Tao Chen ◽

Lin Shao ◽

Tou-Wen Fan ◽

Ning Ding ◽

Jin Yang ◽

...

Keyword(s):

Thermodynamic Property ◽

Ab Initio ◽

Lattice Distortion ◽

Ab Initio Study ◽

Local Lattice Distortion ◽

High Entropy ◽

Local Lattice ◽

Hexagonal Closed Packed

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Theoretical Study of the Local Lattice Distortion at the Trigonal Cr3+ Center in BiI3

Zeitschrift für Naturforschung A ◽

10.1515/zna-2006-1-212 ◽

2006 ◽

Vol 61 (1-2) ◽

pp. 78-82 ◽

Cited By ~ 1

Author(s):

Shao-Yi Wu ◽

Xiu-Ying Gao ◽

Hui-Ning Dong

Keyword(s):

Lattice Distortion ◽

Theoretical Study ◽

Impurity Center ◽

Cluster Approach ◽

Pure Crystal ◽

Local Lattice Distortion ◽

Trigonal Symmetry ◽

Local Lattice ◽

Epr Parameters ◽

Local Angle

The local lattice distortion at the trigonal Cr3+ center in BiI3 is theoretically studied by the perturbation formulas of the EPR parameters for a 3d3 ion in trigonal symmetry, based on the cluster approach. In these formulas the contributions from the s-orbitals of the ligands, which were often ignored, are taken into account. It is found that the local angle β (between the direction of the impurityligand bonding R and the C3 axis) in the impurity center is smaller than the host angle βH in the pure crystal. The calculated EPR parameters are improved compared to those in absence of the ligand s-orbital contributions. The local lattice distortion obtained in this work is discussed.

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Lattice Distortion and Phase Stability of Pd-Doped NiCoFeCr Solid-Solution Alloys

Entropy ◽

10.3390/e20120900 ◽

2018 ◽

Vol 20 (12) ◽

pp. 900 ◽

Cited By ~ 10

Author(s):

Fuxiang Zhang ◽

Yang Tong ◽

Ke Jin ◽

Hongbin Bei ◽

William Weber ◽

...

Keyword(s):

Long Range ◽

Lattice Distortion ◽

Maximum Pressure ◽

Local Lattice Distortion ◽

X Ray ◽

High Entropy ◽

Local Lattice ◽

Pd Doping ◽

Fcc Phase ◽

The Stability

In the present study, we have revealed that (NiCoFeCr)100−xPdx (x= 1, 3, 5, 20 atom%) high-entropy alloys (HEAs) have both local- and long-range lattice distortions by utilizing X-ray total scattering, X-ray diffraction, and extended X-ray absorption fine structure methods. The local lattice distortion determined by the lattice constant difference between the local and average structures was found to be proportional to the Pd content. A small amount of Pd-doping (1 atom%) yields long-range lattice distortion, which is demonstrated by a larger (200) lattice plane spacing than the expected value from an average structure, however, the degree of long-range lattice distortion is not sensitive to the Pd concentration. The structural stability of these distorted HEAs under high-pressure was also examined. The experimental results indicate that doping with a small amount of Pd significantly enhances the stability of the fcc phase by increasing the fcc-to-hcp transformation pressure from ~13.0 GPa in NiCoFeCr to 20–26 GPa in the Pd-doped HEAs and NiCoFeCrPd maintains its fcc lattice up to 74 GPa, the maximum pressure that the current experiments have reached.

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