Theoretical investigation of transition metals (subgroup = 8, 9, 10 and 11) substituted (MgO)9 nanotube clusters

2019 ◽  
Vol 33 (36) ◽  
pp. 1950459 ◽  
Author(s):  
Zhen Zhao ◽  
Zhi Li

The structures, electronic and magnetic properties of the transition metals (TMs) (subgroup = 8, 9, 10 and 11) substituted [Formula: see text] nanotube clusters have been investigated using first-principles at the PBE functional. The results show that as for the [Formula: see text] clusters, [Formula: see text] atoms and Re atoms prefer to substitute the Mg atoms which occupy the edge position of the [Formula: see text] nanotube clusters, while [Formula: see text] and [Formula: see text] atoms prefer to substitute the Mg atoms which occupy the middle hexagonal ring [Formula: see text] nanotube clusters expect for Re atoms. The [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]O9 clusters are more stable than other TMs-substituted [Formula: see text] nanotube clusters. TM substituting significantly improves the kinetic activity of the [Formula: see text] nanotube clusters. The HOMO and LUMO states display evident hybridization between the TMs [Formula: see text] and O [Formula: see text] band states. A few [Formula: see text] orbital electrons of the TM atoms transfers to O atoms. As for the spins of the [Formula: see text] TM atoms for the ground state [Formula: see text] and [Formula: see text] (subgroup = 8, 9, 10 and 11) clusters, [Formula: see text].

2019 ◽  
Vol 33 (22) ◽  
pp. 1950254 ◽  
Author(s):  
Zhi Li ◽  
Zhen Zhao ◽  
Qi Wang ◽  
Tong-Tong Shi

To understand sulfide inclusions in the steel industry, the structures, stabilities, electronic and magnetic properties of the Mn[Formula: see text]S and Mn[Formula: see text]S2 (n=1–6) clusters are investigated by using first-principles. The results show that the S atoms prefer to occupy the outside surface center of the Mn[Formula: see text] (n = 3–6) clusters. Chiral isomers are occurred to the Mn5S2 isomers. The Mn2S, Mn2S2 clusters are more stable than their neighbors. However, the MnS, S2, and Mn5I2 clusters possess higher dynamic stability than their neighbors by the HOMO–LUMO gaps. The Mn[Formula: see text]S and Mn[Formula: see text]S2 (n = 1–6) clusters prefer to spontaneous generation by Gibbs free energy. A few 4s orbital electrons of Mn atoms transferred to the S atoms by Mülliken population analysis. For the other Mn[Formula: see text]S (n = 1–6) clusters, the spin density (17.256) of the ground-state Mn6S clusters is the largest. For the Mn[Formula: see text]S2 (n = 1–6) clusters, the total spin (9.604) of the ground-state Mn2S2 cluster is the largest.


2017 ◽  
Vol 16 (04) ◽  
pp. 1750033 ◽  
Author(s):  
Yuan You

We investigate the effects of vacancies on the electronic and magnetic properties in fully-hydrogenated boron nitride sheet by performing first-principles calculation. Our results reveal that this sheet fosters magnetic materials with finite magnetic moment under certain vacancies. This phenomenon can be explained by the charge redistribution in which the unpaired electrons in bands determine the magnitude of magnetic moment and thus the ground state of the systems. The magnetic moment can be tuned from 0 to 2 by introducing different vacancies. This picture explicitly demonstrates that the type of vacancy plays an important role in determining nonmagnetic or magnetic materials of fully-hydrogenated boron nitride sheet, indicating their functionalities and possible applications in spintronics.


2016 ◽  
Vol 3 (1) ◽  
pp. 89 ◽  
Author(s):  
Shalika Ram Bhandari ◽  
Ram Kumar Thapa ◽  
Madhav Prasad Ghimire

<p>Electronic and magnetic properties of La<sub>4</sub>Ba<sub>2</sub>Cu<sub>2</sub>O<sub>10</sub> had been studied by first-principles density functional theory (DFT). Based on the DFT calculation La<sub>4</sub>Ba<sub>2</sub>Cu<sub>2</sub>O<sub>10</sub> is found to have a ferromagnetic (FM) ground state. The material undergo charge-transfer type insulator to Mott-Hubbard type insulator transition which happens due to strong correlation in La-4f and Cu-3d states. Our results show that the 3d electrons of Cu hybridize strongly with O-2p states near the Fermi level giving rise to the insulating state of La<sub>4</sub>Ba<sub>2</sub>Cu<sub>2</sub>O<sub>10</sub>. Our study suggests that the enhanced magnetic moment is a result of itinerant exchange rather than the exchange interaction involving individual ions of Cu atoms. The total magnetic moment calculated in the present studies is 2 μ<sub>B</sub> per unit cell for La<sub>4</sub>Ba<sub>2</sub>Cu<sub>2</sub>O<sub>10</sub>.</p><p>Journal of Nepal Physical Society Vol.3(1) 2015: 89-96</p>


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