Ferromagnetism in carbon-doped ZnO films from first-principle study

Wang, Xiaofang; Chen, Xiaoshuang; Dong, Ruibin; Huang, Yan; Lü, Wei

doi:10.1016/j.physleta.2009.06.049

Cited by 31 publications

(17 citation statements)

References 30 publications

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“…The presence of the unpaired electron in one of the C(S) sites for 2S + I is also confirmed with the strong C 2p weight at the Fermi level, similar to the 1S situation of Figure 2, where 2 unpaired electrons were present. Finally, note that the magnetic moment of 0.33 µ B /C calculated for the 2S + I and shown in Table I With the considerations above, the magnetism present in the 2S + I calculation can be attributed to the p − p coupling mechanism, which has been suggested for the similar case of ZnO:C. 6,7,31 The unpaired C(S) 2p electrons which do not participate in the ordinary C-C, C-In, or double C=C bonds act to form an impurity band near the Fermi level. The resultant strong DOS at the Fermi level allows for the long ranged p−p exchange mechanism to act between the distant clusters.…”

Section: Discussionmentioning

confidence: 53%

Room-temperature ferromagnetism via unpaired dopant electrons andp−pcoupling in carbon-doped In2O3
Green
¹
,
Boukhvalov
²
,
Kurmaev
³

et al. 2012
Phys. Rev. B
35
1
12
0
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Observations of magnetism in semiconductors doped with nonmagnetic atoms (C, N, etc.) show promise for spintronics applications, but pose an interesting challenge for conventional theories of magnetism. In this work, the magnetic semiconductor carbon-doped In2O3 is studied using theoretical and experimental techniques. Density functional theory calculations predict that ferromagnetism can exist near room temperatures when substitutional carbon atoms have a formally unpaired 2p electron that does not participate in bonding. The unpaired 2p electrons lead to an impurity band near the Fermi level and consequent enhanced density of states which accommodates a strong p − p coupling between local magnetic moments. The unpaired electrons and ferromagnetic coupling are found to arise from a combination of interstitial and substitutional carbon atoms in close proximity. Finally, experimental measurements on samples with varying magnetic properties verify the importance of both strong C 2p character at the Fermi level and strong C 2sp -In 4d hybridization for yielding room temperature ferromagnetism. These results shed light on the interesting field of nonmagnetic dopants inducing ferromagnetism in semiconductors.

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Section: Discussionmentioning

confidence: 53%

Room-temperature ferromagnetism via unpaired dopant electrons andp−pcoupling in carbon-doped In2O3
Green
¹
,
Boukhvalov
²
,
Kurmaev
³

et al. 2012
Phys. Rev. B
35
1
12
0
View full text Add to dashboard Cite

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“…The optoelectronic properties of Ga-and Al-doped ZnO thin films were found to have the good conductivity and transparence [34]. The C-doped ZnO thin films were studied, and they were found to be ferromagnetic [35]. C-doped (ZnO) n (n = 1-12) clusters were studied, and it was found that the substitutional C impurity is more favorable than interstitial C impurity in C-doped (ZnO) n clusters [36].…”

Section: Introductionmentioning

confidence: 99%

DFT investigation on molecular structures of metal and nonmetal-doped ZnO sodalite-like cage and their electronic properties

2015

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The optimized structures of the ZnO sodalite-like cages (ZnOSLs) doped by single metal atoms (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Pd, Ag, Pt and Au) and single nonmetal atoms (B, C, N, Al, Si, P, Ga and Ge) were obtained using DFT/B3LYP method. The energetics and thermodynamic properties for doping processes of single metal atom to Zn V of the Zn vacancy defect ZnOSL surface, (ZnOSL ? Zn V ) and nonmetal atom to O V of the O vacancy defect ZnOSL surface, (ZnOSL ? O V ) were obtained. The binding abilities of transition metal dopants to Zn V of [ZnOSL ? Zn V ] and nonmetal dopants to O V of [ZnOSL ? O V ] surfaces are in orders: Crrespectively. Energy gaps and NBO partial charges for low-spin and high-spin states of metal and nonmetal-doped ZnOSLs and their analyses are reported. Graphical Abstract Keywords Low-spin Á High-spin state Á ZnO sodalite-like cage Á Metal doping Á Nonmetal doping Á DFT Á NBO Electronic supplementary material The online version of this article (

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“…22−24 Different studies have also revealed that ferromagnetism in C-doped ZnO films may be originated due to the presence of C atoms in a high valence state, such as C 4+ , located at Zn sites. 25,26 Nitrogen-doped multiwalled carbon nanotubes (CN XMWNTs) are more chemically reactive 27−29 and become a suitable substrate material for the deposition of different types of nanoparticles, where the nitrogen atoms act as an important promoter of nanoparticle nucleation. 30 −33 In addition, the use of CN X -MWNTs avoids the use of hazardous strong acidic treatments due to its inherent chemical activity.…”

Section: Introductionmentioning

confidence: 99%

Self-Assembly Synthesis of Decorated Nitrogen-Doped Carbon Nanotubes with ZnO Nanoparticles: Anchoring Mechanism and the Effects of Sulfur

Gracia‐Espino

López–Urías

Terrones³

et al. 2014

J. Phys. Chem. C

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Hybrid systems consisting of ZnO nanoparticles (ZnO-NPs) anchored on the surface of nitrogen-doped multiwalled carbon nanotubes (CN XMWNTs) have been synthesized. The anchoring process consists of a selfassembly method involving the mixing of CN X -MWNTs in a solution with N,Ndimethylformamide, zinc acetylacetonate, and thiophene. Thiophene is used as a capping agent for controlling the size and distribution of ZnO-NPs, as well as an anchoring element between the NPs and the nanotube walls. Scanning and transmission electron microscopy characterization revealed that the ZnO-NPs are homogeneously deposited on the surface of CN X -MWNTs. X-ray powder diffraction analysis demonstrated that the ZnO-NPs exhibit a Wurtzite-type crystal structure with an average particle diameter of 5 nm. We also show that the ZnO-NPs do not exhibit a preferential growth direction with respect to the nanotube surface, and their formation is simply controlled by the concentration of the passivating agent. Density functional theory (DFT) calculations confirm that sulfur (from thiophene) is an effective passivating agent for ZnO by preferentially binding low-coordinated Zn atoms. However, the ZnO-NPs could be chemically bonded to the nanotubes through oxygen atoms close to the nitrogenated sites of the tubes. Our results also demonstrate that isolated and sulfur passivated ZnO-NPs become magnetic and exhibit half-metallicity (electronic states with only one spin component are present at the Fermi level). Sulfur-passivated ZnO retains these properties even after forming ZnO/CN X -MWNT hybrid materials.

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Ferromagnetism in carbon-doped ZnO films from first-principle study

Cited by 31 publications

References 30 publications

Room-temperature ferromagnetism via unpaired dopant electrons andp−pcoupling in carbon-doped In2O3
Green
¹
,
Boukhvalov
²
,
Kurmaev
³

et al. 2012
Phys. Rev. B
35
1
12
0
View full text Add to dashboard Cite

Room-temperature ferromagnetism via unpaired dopant electrons andp−pcoupling in carbon-doped In2O3
Green
¹
,
Boukhvalov
²
,
Kurmaev
³

et al. 2012
Phys. Rev. B
35
1
12
0
View full text Add to dashboard Cite

DFT investigation on molecular structures of metal and nonmetal-doped ZnO sodalite-like cage and their electronic properties

Self-Assembly Synthesis of Decorated Nitrogen-Doped Carbon Nanotubes with ZnO Nanoparticles: Anchoring Mechanism and the Effects of Sulfur

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Ferromagnetism in carbon-doped ZnO films from first-principle study

Cited by 31 publications

References 30 publications

Room-temperature ferromagnetism via unpaired dopant electrons andp−pcoupling in carbon-doped In2O3Green1, Boukhvalov2, Kurmaev3 et al. 2012Phys. Rev. B351120View full textAdd to dashboardCite

Room-temperature ferromagnetism via unpaired dopant electrons andp−pcoupling in carbon-doped In2O3Green1, Boukhvalov2, Kurmaev3 et al. 2012Phys. Rev. B351120View full textAdd to dashboardCite

DFT investigation on molecular structures of metal and nonmetal-doped ZnO sodalite-like cage and their electronic properties

Self-Assembly Synthesis of Decorated Nitrogen-Doped Carbon Nanotubes with ZnO Nanoparticles: Anchoring Mechanism and the Effects of Sulfur

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Product

Resources

About

Room-temperature ferromagnetism via unpaired dopant electrons andp−pcoupling in carbon-doped In2O3
Green
¹
,
Boukhvalov
²
,
Kurmaev
³

et al. 2012
Phys. Rev. B
35
1
12
0
View full text Add to dashboard Cite

Room-temperature ferromagnetism via unpaired dopant electrons andp−pcoupling in carbon-doped In2O3
Green
¹
,
Boukhvalov
²
,
Kurmaev
³

et al. 2012
Phys. Rev. B
35
1
12
0
View full text Add to dashboard Cite