中国物理B ›› 2020, Vol. 29 ›› Issue (7): 77505-077505.doi: 10.1088/1674-1056/ab8d9f

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Gd impurity effect on the magnetic and electronic properties of hexagonal Sr ferrites: A case study by DFT

Masomeh Taghipour, Mohammad Yousefi, Reza Fazaeli, Masoud Darvishganji   

  1. 1 Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran;
    2 Department of Chemistry, Yadegar-e-Imam Khomeni(RAH) shahr-e-Rey Branch, Islamic Azad University, Tehran, Iran;
    3 Department of Chemistry, South Tehran Branch, Islamic Azad University, Tehran, Iran;
    4 Department of Chemistry, Qaemshahr Branch, Islamic Azad University, Qaemshahr, Iran
  • 收稿日期:2020-01-22 修回日期:2020-03-31 出版日期:2020-07-05 发布日期:2020-07-05
  • 通讯作者: Mohammad Yousefi E-mail:myousefi50@hotmail.com

Gd impurity effect on the magnetic and electronic properties of hexagonal Sr ferrites: A case study by DFT

Masomeh Taghipour1, Mohammad Yousefi2, Reza Fazaeli3, Masoud Darvishganji4   

  1. 1 Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran;
    2 Department of Chemistry, Yadegar-e-Imam Khomeni(RAH) shahr-e-Rey Branch, Islamic Azad University, Tehran, Iran;
    3 Department of Chemistry, South Tehran Branch, Islamic Azad University, Tehran, Iran;
    4 Department of Chemistry, Qaemshahr Branch, Islamic Azad University, Qaemshahr, Iran
  • Received:2020-01-22 Revised:2020-03-31 Online:2020-07-05 Published:2020-07-05
  • Contact: Mohammad Yousefi E-mail:myousefi50@hotmail.com

摘要: The electronic and magnetic properties of strontium hexa-ferrite (SrFe12O19) are studied in pure state (SrFe12O19) and with dopant in the positions 2 and 3 of Fe atoms (SrGdFe11O19-I and SrGdFe11O19-Ⅱ, respectively) by utilizing a variety of the density functional theory (DFT) approaches including the Perdew-Burke-Ernzerhof generalized gradient approximation (PBE-GGA) and GGA plus Hubbard U parameter (GGA+U). The pure SrFe12O19 is a hard magnetic half-metal with an integer magnetic moment of 64.00μB, while using the GGA+U functional, the magnetic intensity increases, resulting in a magnetic semiconductor with a high integer magnetic moment of 120μB. By doping the Gd atom in the two different positions of Fe, the magnetic moment is increased to 71.68μB and 68.00μB, respectively. The magnetic moment increases and remains an integer; hence, SrGdFe11O19-Ⅱ can be very useful for application in magnetic memories. Moreover, applying the Hubbard parameter turns SrGdFe11O19-I and SrGdFe11O19-Ⅱ to magnetic semiconductors with a magnetic moment of 124μB, and the energy gap of both doped structures at spin down is found to be less than the pure case. By studying the electronic density diagram of the atoms of the crystal, it is found that the major effect to create magnetization in the pure case is due to the Fe atom. However, in the doped case, the elements Gd and Fe have the highest moment in the crystal respectively.

关键词: magnetic properties, density functional theory, half-metal, doping

Abstract: The electronic and magnetic properties of strontium hexa-ferrite (SrFe12O19) are studied in pure state (SrFe12O19) and with dopant in the positions 2 and 3 of Fe atoms (SrGdFe11O19-I and SrGdFe11O19-Ⅱ, respectively) by utilizing a variety of the density functional theory (DFT) approaches including the Perdew-Burke-Ernzerhof generalized gradient approximation (PBE-GGA) and GGA plus Hubbard U parameter (GGA+U). The pure SrFe12O19 is a hard magnetic half-metal with an integer magnetic moment of 64.00μB, while using the GGA+U functional, the magnetic intensity increases, resulting in a magnetic semiconductor with a high integer magnetic moment of 120μB. By doping the Gd atom in the two different positions of Fe, the magnetic moment is increased to 71.68μB and 68.00μB, respectively. The magnetic moment increases and remains an integer; hence, SrGdFe11O19-Ⅱ can be very useful for application in magnetic memories. Moreover, applying the Hubbard parameter turns SrGdFe11O19-I and SrGdFe11O19-Ⅱ to magnetic semiconductors with a magnetic moment of 124μB, and the energy gap of both doped structures at spin down is found to be less than the pure case. By studying the electronic density diagram of the atoms of the crystal, it is found that the major effect to create magnetization in the pure case is due to the Fe atom. However, in the doped case, the elements Gd and Fe have the highest moment in the crystal respectively.

Key words: magnetic properties, density functional theory, half-metal, doping

中图分类号:  (Magnetic properties of nanostructures)

  • 75.75.-c
71.15.Mb (Density functional theory, local density approximation, gradient and other corrections) 61.72.-y (Defects and impurities in crystals; microstructure)