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First-principles Study of the Electronic, Magnetic and Structural Properties of ZnO and Zn1-xCrxO (x = 0.125, 0.25, 0.375, 0.5) in the Room Temperature Wurtzite Structure


Affiliations
1 Department of Physics, Taki Government College, P.O. Taki, North 24 Dist, Parganas 743 429, India
 

First-principles electronic structure calculations were presented to study the electronic, magnetic and structural properties of pure ZnO and Zn1-xCrxO (x = 0.125, 0.25, 0.375, 0.5) in the room temperature (293 K) wurtzite structure. Pure ZnO is found to be a non-magnetic insulator due to perfectly paired electrons in each Zn-3d orbital. This material encounters nonmagnetic insulator to a ferromagnetic half-metal for x 0.125 and then to a ferro^magnetic ^metal for x = 0.25. The ferromagnetic metallic phase maintains up to x = 0.5. It is revealed in this study that 100% spin polarization is responsible for the half-metallic behaviour of Zn0.875Cr0.125O. Nevertheless, partial filling of Cr-3d3z2-r2 orbital in the spin-up channel together with a minute, but finite contribution of electrons from the Cr-3dxy/z2- r2 orbitals at EF for the spin-down channel are together responsible for the metallic behaviour of Zn1-xCrxO (x ≥ 0.25). The ferromagnetism in all the Cr-substituted compounds arises from strong Hund’s rule coupling. Eventually, a trivial variation in the Zn-O/Zn-Zn bond distances and ZZn-O-Zn bond angles caused by Cr doping is responsible for a minor structural distortion in Zn0.5Cr0.5O.

Keywords

Bandgap Semiconductor, Cr-Doped ZnO,, Electronic And Optical Properties, Density Functional Theory, Wurtzite ZnO,
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  • First-principles Study of the Electronic, Magnetic and Structural Properties of ZnO and Zn1-xCrxO (x = 0.125, 0.25, 0.375, 0.5) in the Room Temperature Wurtzite Structure

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Authors

Sarajit Biswas
Department of Physics, Taki Government College, P.O. Taki, North 24 Dist, Parganas 743 429, India

Abstract


First-principles electronic structure calculations were presented to study the electronic, magnetic and structural properties of pure ZnO and Zn1-xCrxO (x = 0.125, 0.25, 0.375, 0.5) in the room temperature (293 K) wurtzite structure. Pure ZnO is found to be a non-magnetic insulator due to perfectly paired electrons in each Zn-3d orbital. This material encounters nonmagnetic insulator to a ferromagnetic half-metal for x 0.125 and then to a ferro^magnetic ^metal for x = 0.25. The ferromagnetic metallic phase maintains up to x = 0.5. It is revealed in this study that 100% spin polarization is responsible for the half-metallic behaviour of Zn0.875Cr0.125O. Nevertheless, partial filling of Cr-3d3z2-r2 orbital in the spin-up channel together with a minute, but finite contribution of electrons from the Cr-3dxy/z2- r2 orbitals at EF for the spin-down channel are together responsible for the metallic behaviour of Zn1-xCrxO (x ≥ 0.25). The ferromagnetism in all the Cr-substituted compounds arises from strong Hund’s rule coupling. Eventually, a trivial variation in the Zn-O/Zn-Zn bond distances and ZZn-O-Zn bond angles caused by Cr doping is responsible for a minor structural distortion in Zn0.5Cr0.5O.

Keywords


Bandgap Semiconductor, Cr-Doped ZnO,, Electronic And Optical Properties, Density Functional Theory, Wurtzite ZnO,

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DOI: https://doi.org/10.18520/cs%2Fv115%2Fi8%2F1504-1511