Average and Local Crystal Structure and Electronic Structure of 0.4Li2MnO3-0.6LiMn1/3Ni1/3Co1/3O2 Using First-principles Calculations and Neutron Beam and Synchrotron X-Ray Sources

When processing single crystal X-ray diffraction datasets for twins of Al2Cu sample synthesized by the high-pressure sintering (HPS) method, we have clarified why the crystal structure of Al2Cu was incorrectly solved about a century ago. The structural relationships between all existing Al2Cu phases, including the Owen-, θ-, θ’-, and Ω-Al2Cu phases, were investigated and established based on a proposed pseudo Al2Cu phase. Two potential phases have been built up by adjusting the packing sequences of A/B layers of Al atoms that were inherent in all existing Al2Cu phases. The mechanical, thermal, and dynamical stability of two such novel phases and their electronic properties were investigated by first-principles calculations.

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Investigation on Average and Local Crystal Structures and Electronic Structure Change of Li-Rich Solid Solution Cathode Material 0.4Li2MnO3-0.6LiMn1/3Ni1/3Co1/3O2 during Charge-Discharge Process Using Neutron Beam and Synchrotron X-Ray Sources and First-Principles Calculations

ECS Meeting Abstracts ◽

10.1149/ma2016-03/2/1007 ◽

2016 ◽

Keyword(s):

Solid Solution ◽

Electronic Structure ◽

Cathode Material ◽

Crystal Structures ◽

First Principles ◽

Structure Change ◽

Discharge Process ◽

First Principles Calculations ◽

X Ray ◽

Charge Discharge

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Structural analysis of Gd6FeBi2 from single-crystal X-ray diffraction methods and electronic structure calculations

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229619004868 ◽

2019 ◽

Vol 75 (5) ◽

pp. 562-567 ◽

Cited By ~ 4

Author(s):

Jiliang Zhang ◽

Yong-Mook Kang ◽

Guangcun Shan ◽

Svilen Bobev

Keyword(s):

Electronic Structure ◽

Single Crystal ◽

First Principles ◽

Earth Metal ◽

Magnetic Ordering ◽

Additional Contribution ◽

First Principles Calculations ◽

X Ray Diffraction ◽

Magnetic Exchange ◽

X Ray

The crystal structure of the gadolinium iron bismuthide Gd6FeBi2 has been characterized by single-crystal X-ray diffraction data and analyzed in detail using first-principles calculations. The structure is isotypic with the Zr6CoAl2 structure, which is a variant of the ZrNiAl structure and its binary prototype Fe2P (Pearson code hP9, Wyckoff sequence g f d a). As such, the structure is best viewed as an array of tricapped trigonal prisms of Gd atoms centered alternately by Fe and Bi. The magnetic-ordering temperature of this compound (ca 350 K) is much higher than that of other rare-earth metal-rich phases with the same or related structures. It is also higher than the ordering temperature of many other Gd-rich ternary phases, where the magnetic exchange is typically governed by Ruderman–Kittel–Kasuya–Yosida (RKKY) interactions. First-principles calculations reveal a larger than expected Gd magnetic moment, with the additional contribution arising from the Gd 5d electrons. The electronic structure analysis suggests strong Gd 5d–Fe 3d hybridization to be the cause of this effect, rather than weak interactions between Gd and Bi. These details are of importance for understanding the magnetic response and explaining the high ordering temperature in this material.

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