Ferromagnetism in undoped semiconductors

2011 ◽  
Vol 1370 ◽  
Author(s):  
Yandong Ma ◽  
Ying Dai ◽  
Baibiao Huang
Keyword(s):  
Spin Polarization ◽  
Magnetic Moment ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Local Magnetic Moment ◽  
Semiconductor Materials ◽  
Ferromagnetic Coupling ◽  
Dangling Bonds ◽  
Ferromagnetic Properties ◽  
Cation Vacancies

ABSTRACTThe so-called “d0” magnetism observed in semiconductors, which is not caused by partially filled d orbitals, has challenged our conventional understanding on the origin of magnetism. One class of semiconductor materials showing d0 ferromagnetism is undoped oxides and nitrides. Here, we review the ferromagnetic properties of undoped GaN and MgO based on our recent investigations. It is revealed that the room-temperature ferromagnetism originates from the anion dangling bonds associated with the surface cation-vacancies. And the magnetism of ferromagnetic coupling between the vacancy induced local magnetic moment by through-bond spin polarization in undoped semiconductors is reviewed according to our works.

The Magnetic Ordering of SiCN Films Prepared by Ion Implantation

2012 ◽  
Vol 531-532 ◽  
pp. 325-328
Author(s):  
Xu Dong Meng ◽  
Fu Yang ◽  
Xiao Yu Liu
Keyword(s):  
Ion Implantation ◽  
Spin Polarization ◽  
Magnetic Moment ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Magnetic Ordering ◽  
Local Magnetic Moment ◽  
Vacancy Defects ◽  
Sic Films ◽  
Implantation Dosage

Room-temperature ferromagnetism was observed in the SiCN films prepared by ion implantation. The result indicates that N ion implantation dosage in the film has great effect on the observed room-temperature ferromagnetism of the films. Along with the increase of ion implantation dosage, the N ions increase and the magnetism enhances. Because of the ion implantation will cause a lot of defects on the surface of SiC films, which will induce a lot of vacancies. The C atoms are replaced by the N ions doped, the concentration of the N ions decides the charges states and spin polarizations of Si vacancy defects. Local magnetic moment is induced because of the spin polarization of the Si vacancy defects, and the films show ferromagnetic properties.Charge states and spin polarizations of silicon vacancy defects can be manipulated by N atoms which induces the ferromagnetism.

Effect of Ho dopant on the ferromagnetic characteristics of MoS2 nanocrystals

2019 ◽  
Vol 21 (1) ◽  
pp. 232-237 ◽  
Author(s):  
Qi Zhao ◽  
Chengbo Zhai ◽  
Qing Lu ◽  
Mingzhe Zhang
Keyword(s):  
Magnetic Moment ◽  
Room Temperature ◽  
Doping Concentration ◽  
Room Temperature Ferromagnetism

The as-synthesized Ho-doped MoS2 nanocrystals show intrinsic room-temperature ferromagnetism and their magnetic moment can be tuned by the doping concentration.

scholarly journals Electrical control of carriers' spin orientation in the FeVTiSi Heusler alloy

2015 ◽  
Vol 3 (11) ◽  
pp. 2563-2567 ◽  
Author(s):  
Jiahui Zhang ◽  
Xingxing Li ◽  
Jinlong Yang
Keyword(s):  
Spin Polarization ◽  
Heusler Alloy ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Polarization Direction ◽  
Spin Orientation ◽  
Electrical Control ◽  
Carrier Doping

Control of the spin-polarization direction by carrier doping in a quaternary Heusler alloy FeVTiSi with a bipolar magnetic semiconducting character and room temperature ferromagnetism.

Synthesis and room-temperature ferromagnetism of cobalt-doped SnO2 nanowires

2009 ◽  
Vol 24 (6) ◽  
pp. 2001-2005 ◽  
Author(s):  
Jin Wu ◽  
Ke Yu ◽  
Yongsheng Zhang ◽  
Lijun Li ◽  
Ziqiang Zhu
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Chemical Vapor ◽  
Average Diameter ◽  
Magnetization Measurement ◽  
Chemical Vapor Transport ◽  
Ferromagnetic Properties ◽  
Transmission Electron ◽  
Sno2 Nanowires ◽  
Ferromagnetic Hysteresis

We have observed ferromagnetism in dilute cobalt-doped SnO2 nanowires at room temperatures. The Co-doped SnO2 nanowires with an average diameter of ∼50 nm were synthesized by the thermal chemical vapor transport method. High-resolution transmission electron microscopy and energy-dispersive x-ray spectroscopy analyses demonstrate that the nanowires are single-crystal structures and Co is homogeneously doped into the SnO2 lattice. The ferromagnetic hysteresis curves and temperature-dependent magnetization measurement provide evidence for ferromagnetic properties with a Curie temperature above room temperature. Oxygen annealing has been performed to study the roles played by the oxygen vacancies in determining the ferromagnetic properties of the nanowires.

Ferromagnetism properties of Er-doped ZnO: a GGA + U study

RSC Advances ◽  
2016 ◽  
Vol 6 (109) ◽  
pp. 107865-107870 ◽  
Author(s):  
Sanjun Wang ◽  
Xiaobo Shi ◽  
Jinming Li
Keyword(s):  
Magnetic Moment ◽  
First Principles ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
First Principles Calculation ◽  
Doped Zno ◽  
Er Doped ◽  
Zn Vacancy

Our first-principles calculation finds that only the Zn vacancy can induce a 1.0 μB magnetic moment in Er-doped ZnO, which comes from the unpaired 2p electrons at the ligand O atom and results in the room-temperature ferromagnetism property of ZnO.

Room-temperature ferromagnetism in Co doped MoS2 sheets

2015 ◽  
Vol 17 (24) ◽  
pp. 15822-15828 ◽  
Author(s):  
ZhongCheng Xiang ◽  
Zhong Zhang ◽  
XiJin Xu ◽  
Qin Zhang ◽  
QingBao Wang ◽  
...  
Keyword(s):  
Magnetic Moment ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Co Doped

We synthesized MoS2 nanosheets with varying Co dopant concentrations; the result implied that the values of the magnetic moment decreased with the increase of the Co dopant concentrations.

Role of multivalent Cu, oxygen vacancies and CuO nanophase in the ferromagnetic properties of ZnO:Cu thin films

RSC Advances ◽  
2015 ◽  
Vol 5 (69) ◽  
pp. 55648-55657 ◽  
Author(s):  
M. Younas ◽  
Junying Shen ◽  
Mingquan He ◽  
R. Lortz ◽  
Fahad Azad ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Room Temperature ◽  
Oxygen Vacancies ◽  
Room Temperature Ferromagnetism ◽  
Simultaneous Presence ◽  
Ferromagnetic Properties

Room temperature ferromagnetism (FM) of these thin film samples are highly tuneable by the simultaneous presence of CuO nanophases and multivalent Cu and Vö concentrations.

Room temperature ferromagnetic properties of dysprosium-doped tris(8-hydroxyquinoline) aluminum: experimental and theoretical investigation

RSC Advances ◽  
2016 ◽  
Vol 6 (49) ◽  
pp. 43780-43785 ◽  
Author(s):  
Feng Jiang ◽  
Zhiyong Pang ◽  
Huimin Yuan ◽  
Zhixian Wei ◽  
Wanfeng Xie ◽  
...  
Keyword(s):  
Theoretical Investigation ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Ferromagnetic Properties

Room-temperature ferromagnetism was observed in a Dy-doped Alq3 film.

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