https://doi.org/10.1140/epjb/s10051-023-00500-7
Regular Article - Solid State and Materials
Role of spin-orbit coupling effects in rare-earth metallic tetra-borides: a first principle study
1
Department of Physics, Bajkul Milani Mahavidyalaya, 721655, Purba Medinipur, West Bengal, India
2
Department of Physics, Kazi Nazrul University, 713340, Asansol, West Bengal, India
Received:
4
December
2022
Accepted:
17
February
2023
Published online:
5
March
2023
Recent observation of magnetization plateau in rare-earth metallic tetra-borides, , have drawn lot of attention to this class of materials. In this article, using first principle electronic structure methods (DFT) implemented in Quantum Espresso (QE), we have studied hither-to neglected strong spin-orbit coupling (SOC) effects present in these systems on the electronic structure of these system in the non-magnetic ground state. The calculations were done under GGA and GGA+SO approximations. In the electronic band structure, strong SOC effect lifts degeneracy at various symmetry points. The projected density of states consists of 3 distinct spectral peaks well below the Fermi energy and separated from the continuum density of states around the Fermi energy. The discrete peaks arise due to rare-earth
, rare-earth
+ B
and B
while the continuum states around the Fermi level arises due to hybridized B
, rare-earth
and
orbitals. Upon inclusion of SOC the peak arising due to rare-earth p gets split into two peaks corresponding to
and
configurations. The splitting gap (
) between
and
manifold shows power law (
,
is the atomic number of the rare-earth atom involved) behaviour with n =4.82. In case of
, in the presence of SOC, spin-split
orbitals contributes to density of states at the Fermi level while the density of states at the Fermi level largely remains unaffected for all other materials under consideration.
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