scholarly journals Oxygen Defect-Mediated Magnetism in Fe-C Codoped TiO2

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Zhaorui Zou ◽  
Zhongpo Zhou ◽  
Haiying Wang ◽  
Meng Du
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Spin Coating ◽  
Room Temperature ◽  
Oxygen Vacancies ◽  
Room Temperature Ferromagnetism ◽  
Sol Gel ◽  
Experimental Results ◽  
Oxygen Defect ◽  
First Principles Calculations

The magnetic properties of the C doped and C-Fe codoped TiO2films fabricated by sol-gel and spin coating have been investigated combining experiments and first-principles calculations. All the samples exhibit the anatase crystal phase and the room temperature ferromagnetism. The values of the saturation magnetizations are in the order of Fe-C codoped TiO2> Fe-C codoped TiO2(annealed in O2) > C doped TiO2> C doped TiO2(annealed in O2). The calculated net moment values are in the order of Fe-C codoped TiO2> C doped TiO2with oxygen vacancies existing, in accord with the experimental results. The hybridization of Fe 3d, C 2p,and O 2p(nearest to the Fe defect) led to the spin split of Fe 3d, C 2p,and O 2pwhich contributed to the ferromagnetism.

Room-Temperature Ferromagnetism in Co-Doped SrTiO3 Nanofibres

2012 ◽  
Vol 512-515 ◽  
pp. 1438-1441
Author(s):  
Wei Zhang ◽  
He Ping Li ◽  
Wei Pan
Keyword(s):  
Room Temperature ◽  
Oxygen Vacancies ◽  
Room Temperature Ferromagnetism ◽  
Sol Gel ◽  
Magnetic Ordering ◽  
Second Phase ◽  
Co Doped

In this article, Co-doped SrTiO3 nanofibres have been prepared by electrospinning from a sol-gel precursor and the following calcination at 923K. XRD results confirmed that no second phase was formed, and Co ions successfully occupied the Ti sites. By annealing in hydrogen, oxygen vacancies and (Co-H-Co) were formed, which both contributed to the magnetic ordering in SrTi1-xCoxO3 nanofibres are at 300K.

Effect of Structural Deficiencies on Bi-Ferroic Behaviors of Lead-Free Bi0.5 Na0.40K0.10TiO3 Films

2021 ◽  
Vol 21 (11) ◽  
pp. 5653-5658
Author(s):  
Ngo Due Quan ◽  
Nguyen Due Minh ◽  
Hoang Viet Hung
Keyword(s):  
Magnetic Properties ◽  
Annealing Time ◽  
Spin Coating ◽  
Applied Electric Field ◽  
Remnant Polarization ◽  
Oxygen Vacancies ◽  
Sol Gel ◽  
Lead Free ◽  
Ferroelectric Films ◽  
Si Substrates

Lead-free Bi0.5Na0.4K0.1TiO3 (BNKT) ferroelectric films on Pt/TI/SIO2/Si substrates were prepared via a sol-gel spin coating routine. The microstructures and multiferroic behaviors of the films were examined intimately as a function of the annealing time. A rise of annealing time enhanced the crystallization of the films via the perovskite structure. The multiferroic behavior, including simultaneously the magnetic and ferroelectric orders, was observed altogether the films. When the annealing time rose, ferroelectric and magnetic properties were found significantly increased. The remnant polarization (Pr), also as maximum polarization (Pm) respectively increased to the very best values of 11.5 µC/cm2 and 40.0 µC/cm2 under an applied electric field of 500 kV/cm. The saturated magnetization (Ms) of films increased to 2.3 emu/cm3 for the annealing time of 60 minutes. Oxygen vacancies, originating from the evaporation of metal ions during annealing at high temperatures are attributed to the explanation for ferromagnetism within the BNKT films.

scholarly journals First-principles calculations of GaN:Gd nanowires: Carbon-dopants-induced room-temperature ferromagnetism

AIP Advances ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. 115003 ◽  
Author(s):  
Ruikuan Xie ◽  
Huaizhong Xing ◽  
Yijie Zeng ◽  
Yuan Liang ◽  
Yan Huang ◽  
...  
Keyword(s):  
First Principles ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
First Principles Calculations

scholarly journals Origin of Ferromagnetism in Ru and N Codoped TiO2 Nanotubes: Experiments and Theory Investigations

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Jing Xu ◽  
Zhongpo Zhou ◽  
Haiying Wang
Keyword(s):  
Saturation Magnetization ◽  
First Principles ◽  
Tio2 Nanotubes ◽  
Room Temperature ◽  
Oxygen Vacancies ◽  
Room Temperature Ferromagnetism ◽  
Codoped Tio2

The room temperature ferromagnetism (RTFM) of the undoped, N doped, Ru doped ,and Ru-N codoped anatase TiO2 nanotubes (TNTs) films are investigated combined with experiments and first principles approaches. The experiments are highly consistent with the theory calculations. All samples display anatase structures and ferromagnetism at room temperature. The values of the saturation magnetization (Ms) of undoped TiO2, N doped TiO2, Ru doped TiO2, and Ru-N codoped TiO2, respectively, are 0.065 emu/g, 0.015 emu/g, 0.155 emu/g, and 0.073 emu/g. The calculated net moment is in the order of Ru doped > Ru-N codoped > undoped > N doped. The oxygen vacancies play an important role in RTFM of TNTs. Moreover, the hybridization of Ru 4d, N 2p, and O 2p led to the spin-spilt of Ru 4d, N 2p, and O 2p which is devoted to the system magnetism.

Enhancement of room-temperature ferromagnetism in manganese oxide thin films grown on Nb:SrTiO3 substrates

2014 ◽  
Vol 28 (20) ◽  
pp. 1450162
Author(s):  
P. Hu ◽  
S. X. Wu ◽  
S. W. Li
Keyword(s):  
Thin Films ◽  
Molecular Beam Epitaxy ◽  
Manganese Oxide ◽  
Growth Process ◽  
Room Temperature ◽  
Oxygen Vacancies ◽  
Molecular Beam ◽  
Room Temperature Ferromagnetism ◽  
Experimental Results ◽  
Oxide Thin Films

In this paper, α- Mn 2 O 3 thin films were fabricated by plasma-assisted molecular beam epitaxy on SrTiO 3 and Nb : SrTiO 3, respectively. The grown samples showed room temperature ferromagnetism (RFM) properties. All the experimental results manifested that the RFM properties in undoped thin films were induced by oxygen vacancies formed during the growth process. Even more, the ferromagnetism of thin films grown on Nb : SrTiO 3 were enhanced, and these results confirmed the fact that oxygen vacancies induced ferromagnetism. That is to say, more oxygen vacancies result the more unpaired electrons induced prominent abnormal spin causing ferromagnetism.

SUBTLE INTERPLAY BETWEEN HYDROGEN AND MAGNETISM IN Co DOPED ZnO

2012 ◽  
Vol 01 (01) ◽  
pp. 1250001
Author(s):  
Y. B. ZHANG ◽  
M. H. N. ASSADI ◽  
S. LI
Keyword(s):  
Magnetic Properties ◽  
Point Defect ◽  
First Principles ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Strong Tendency ◽  
Doped Zno ◽  
Co Doped

The effects of hydrogen, either interstitial (HI) or substitutional (Ho), on magnetic properties of Co doped ZnO (ZnO:Co) have been systematically investigated using first-principles density functional calculations. The study discovers the correlation between the distribution of Co ions and the hydrogen point defect and magnetism. It is found that Co ions and hydrogen have a strong tendency toward aggregation and hydrogen mainly contributes to the room temperature ferromagnetism observed experimentally in ZnO:Co . Furthermore, in ZnO:Co , the formation of Ho with four-fold hydrogenic bonds is favored over HI by 0.4 eV.

Room-temperature ferromagnetism in Ni(ii)-chromia based core–shell nanoparticles: experiment and first principles calculations

2018 ◽  
Vol 20 (15) ◽  
pp. 10396-10406 ◽  
Author(s):  
M. D. Hossain ◽  
R. A. Mayanovic ◽  
S. Dey ◽  
R. Sakidja ◽  
M. Benamara
Keyword(s):  
First Principles ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Core Shell ◽  
First Principles Calculations ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

We have synthesized bimagnetic core–shell nanoparticles containing a first-of-its-kind Ni(ii)-chromia nanophase shell and a well-defined, epitaxial core–shell interface.

scholarly journals A DFT investigation of the role of oxygen vacancies on the structural, electronic and magnetic properties of ATiO3 (A = Mn, Fe, Ni) multiferroic materials

2018 ◽  
Vol 20 (45) ◽  
pp. 28382-28392 ◽  
Author(s):  
R. A. P. Ribeiro ◽  
E. Longo ◽  
J. Andrés ◽  
S. R. de Lazaro
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Oxygen Vacancies ◽  
First Principles Calculations ◽  
Deep Insight ◽  
Multiferroic Materials ◽  
Multiferroic Properties ◽  
Surface Models ◽  
Insight Into

In order to achieve deep insight into the multiferroic behavior and electronic properties of intrinsic oxygen vacancies in ATiO3 (A = Mn, Fe, Ni), first-principles calculations were carried out for bulk and non-polar (110) surface models, showing that controlling oxygen vacancies can be a valuable strategy to tailor the multiferroic properties.

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