Electronic structure and nearly room-temperature ferromagnetism in V-doped monolayer and bilayer MoS2

2018 ◽  
Vol 32 (21) ◽  
pp. 1850231 ◽  
Author(s):  
Sintayehu Mekonnen ◽  
Pooran Singh
Keyword(s):  
Electronic Structure ◽  
Room Temperature ◽  
Function Theory ◽  
Magnetic Semiconductors ◽  
Room Temperature Ferromagnetism ◽  
Dilute Magnetic Semiconductors ◽  
Magnetic Interaction ◽  
Dopant Atom ◽  
Ferromagnetic Transition ◽  
Atomic Distance

The electronic structure, magnetic properties and ferromagnetic transition temperature (Tc) of Vandium (V) doped monolayer (ML) and bilayer (BL) MoS2 are investigated using density function theory (DFT) plus on-site Hubbard potential correction (U). The results show that substitution of V dopant atom at the Mo sites are energetically favorable and magnetic interaction between two dopants in ML and BL MoS2 oscillates from ferromagnetic (FM) to antiferromagnetic (AF) depending on atomic distance between dopants. Our result also shows that a pair of V dopants in different layers of BL MoS2 interacts antiferromagnetically. Moreover, it is obtained that interlayer interaction in BL MoS2 affects the magnetic interaction in V-doped BL MoS2. The calculated ferromagnetic transition temperatures (Tc) value for impurity concentration of 12.5% and 22.22% are 242 and 285 K, respectively, for ML phase. However, for BL phase T[Formula: see text] values are 187 and 256 K for concentration of 6.25% and 11.11%, respectively, these values are closer to room-temperature. Our calculations indicate that, V-doped ML and BL MoS2 are promising candidates for 2D dilute magnetic semiconductors for spintronics applications.

scholarly journals Electronic Structure and Room Temperature of 2D Dilute Magnetic Semiconductors in Bilayer MoS2-Doped Mn

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Sintayehu Mekonnen Hailemariam
Keyword(s):  
Electronic Structure ◽  
Room Temperature ◽  
Magnetic Semiconductors ◽  
Magnetic Semiconductor ◽  
Dilute Magnetic Semiconductors ◽  
Magnetic Interaction ◽  
Spatial Distance ◽  
Atomic Distance ◽  
Dilute Limit ◽  
Mn Doped

The electronic structure and magnetic properties of manganese- (Mn-) doped bilayer (BL) molybdenum disulfide (MoS2) are studied using the density function theory (DFT) plus on-site Hubbard potential correction (U). The results show that the substitution of Mn at the Mo sites of BL MoS2 is energetically favorable under sulfur- (S-) rich regime than Mo. The magnetic interaction between the two manganese (Mn) atoms in BL MoS2 is always ferromagnetic (FM) irrespective of the spatial distance between them, but the strength of ferromagnetic interaction decays with atomic distance. It is also found that two dopants in different layers of BL MoS2 communicate ferromagnetically. In addition to this, the detail investigation of BL MoS2 and its counterpart of monolayer indicates that interlayer interaction in BL MoS2 affects the magnetic interaction in Mn-doped BL MoS2. The calculated Curie temperature is 324, 418, and 381 K for impurity concentration of 4%, 6.25%, and 11.11%, respectively, which is greater than room temperature, and the good dilute limit of dopant concentration is 0–6.25%. Based on the finding, it is proposed that Mn-doped BL MoS2 are promising candidates for two-dimensional (2D) dilute magnetic semiconductor (DMS) for high-temperature spintronics applications.

Room temperature ferromagnetism in III–V and II–IV–V2 dilute magnetic semiconductors

2006 ◽  
Vol 374-375 ◽  
pp. 430-432 ◽  
Author(s):  
V.G. Storchak ◽  
D.G. Eshchenko ◽  
H. Luetkens ◽  
E. Morenzoni ◽  
R.L. Lichti ◽  
...  
Keyword(s):  
Room Temperature ◽  
Magnetic Semiconductors ◽  
Room Temperature Ferromagnetism ◽  
Dilute Magnetic Semiconductors

THE GROWTH AND CHARACTERIZATION OF ROOM TEMPERATURE FERROMAGNETIC WIDEBAND-GAP MATERIALS FOR SPINTRONIC APPLICATIONS

2006 ◽  
Vol 16 (02) ◽  
pp. 515-543
Author(s):  
MATTHEW H. KANE ◽  
MARTIN STRASSBURG ◽  
WILLIAM E. FENWICK ◽  
ALI ASGHAR ◽  
IAN T. FERGUSON
Keyword(s):  
Room Temperature ◽  
Magnetic Semiconductors ◽  
Room Temperature Ferromagnetism ◽  
Dilute Magnetic Semiconductors ◽  
Chemical Vapor ◽  
Wide Bandgap ◽  
Organic Chemical ◽  
Ferromagnetic Behavior ◽  
Spintronic Devices

Wide-bandgap dilute magnetic semiconductors (DMS), such as transition-metal doped ZnO and GaN , have gained attention for use in spintronic devices because of predictions and experimental reports of room temperature ferromagnetism which may enable their use in spintronic devices. However, there has been some debate over the source of ferromagnetism in these materials. This paper focuses on the high quality growth of wide bandgap DMS, and the characterization of Zn 1-x Mn x O produced by melt-growth techniques and Ga 1-x Mn x N grown by metal organic chemical vapor deposition (MOCVD). High resolution X-ray diffraction results revealed no second phases in either the ZnO crystals or the GaN films. Undoped as-grown, bulk crystals of Zn 1-x Mn x O and Zn 1-x Co x O crystals are shown to be paramagnetic at all temperatures. In contrast, the Ga 1-x Mn x N films showed ferromagnetic behavior at room temperature under optimum growth conditions. Experimental identification of the Mn ion charge state and the presence of bands in the bandgap of GaN are investigated by optical spectroscopy and electron spin paramagnetic resonance (EPR). It is shown that the broadening of states in the Mn 3d shell scaled with Mn concentration, and that optical transitions due to this band correlated with the strong ferromagnetism in these samples. However, this band disappeared with an increase in free electron concentration provided by either annealing or doping. Raman studies of Ga 1-x Mn x N revealed two predominant Mn -related modes featured with increasing concentration, a broad disorder related structure at 300cm-1 and a sharper peak at 669cm-1 This works show that the development of practical ferromagnetic wide bandgap DMS materials for spintronic applications will require both the lattice site introduction of Mn as well as careful control of the background defect concentration to optimize these materials.

scholarly journals Increased room temperature ferromagnetism in Co-doped tetrahedral perovskite niobates

2021 ◽  
Vol 8 (10) ◽  
Author(s):  
Yi Zhou ◽  
Qing He ◽  
Fei Zhou ◽  
Xingqi Liao ◽  
Yong Liu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Magnetic Semiconductors ◽  
Room Temperature Ferromagnetism ◽  
Dilute Magnetic Semiconductors ◽  
Defect Band ◽  
Co Doping ◽  
Band Absorption ◽  
Local Spin Polarization ◽  
Curie Temperatures ◽  
Co Doped

Dilute magnetic semiconductors (DMSs), such as (In, Mn)As and (Ga, Mn)As prototypes, are limited to III–V semiconductors with Curie temperatures ( T c ) far from room temperature, thereby hindering their wide application. Here, one kind of DMS based on perovskite niobates is reported. BaM x Nb (1− x ) O 3− δ ( M = Fe, Co) powders are prepared by the composite-hydroxide-mediated method. The addition of M elements endows BaM x Nb (1− x ) O 3− δ with local ferromagnetism. The tetragonal BaCo x Nb (1− x ) O 3− δ nanocrystals can be obtained by Co doping, which shows strong saturation magnetization ( M sat ) of 2.22 emu g −1 , a remnant magnetization ( M r ) of 0.084 emu g −1 and a small coercive field ( H c ) of 167.02 Oe at room temperature. The ab initio calculations indicate that Co doping could lead to a 64% local spin polarization at the Fermi level ( E F ) with net spin DOS of 0.89 electrons eV −1 , this result shows the possibility of maintaining strong ferromagnetism at room temperature. In addition, the trade-off effect between the defect band absorption and ferromagnetic properties of BaM x Nb (1− x ) O 3− δ is verified experimentally and theoretically.

Cu and Co codoping effects on room-temperature ferromagnetism of (Co,Cu):ZnO dilute magnetic semiconductors

2011 ◽  
Vol 109 (10) ◽  
pp. 103705 ◽  
Author(s):  
Fengchun Hu ◽  
Qinghua Liu ◽  
Zhihu Sun ◽  
Tao Yao ◽  
Zhiyun Pan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Magnetic Semiconductors ◽  
Room Temperature Ferromagnetism ◽  
Dilute Magnetic Semiconductors

Atom-Probe Tomographic Studies of Thin Films and Multilayers

MRS Bulletin ◽  
2009 ◽  
Vol 34 (10) ◽  
pp. 732-737 ◽  
Author(s):  
David J. Larson ◽  
Alfred Cerezo ◽  
Jean Juraszek ◽  
Kazuhiro Hono ◽  
Guido Schmitz
Keyword(s):  
Thin Films ◽  
Atom Probe Tomography ◽  
Room Temperature ◽  
Film Growth ◽  
Thermal Evolution ◽  
Magnetic Semiconductors ◽  
Room Temperature Ferromagnetism ◽  
Dilute Magnetic Semiconductors ◽  
Atom Probe ◽  
Theory And Modeling

AbstractThis article reviews investigations of the growth and reactions within thin metal and oxide films using atom-probe tomography. Included in this review are (1) studies of interfacial and growth reactions in magnetoresistive metallic, metal/oxide, and magnetic magnetostrictive multilayers; (2) comparison of selected portions of these results to simulated film growth using molecular dynamics; and (3) study of the origin of room-temperature ferromagnetism in dilute magnetic semiconductors. Information of this type is useful in order to understand the formation and thermal evolution of thin films (and to compare to theory and modeling) and, ultimately, to permit further optimization of devices based on thin films.

Bulk Sn1−xMnxO2 magnetic semiconductors without room-temperature ferromagnetism

2006 ◽  
Vol 138 (4) ◽  
pp. 175-178 ◽  
Author(s):  
K.H. Gao ◽  
Z.Q. Li ◽  
X.J. Liu ◽  
W. Song ◽  
H. Liu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Magnetic Semiconductors ◽  
Room Temperature Ferromagnetism

Local electronic structure around Mn and Ga in Mn-doped GaN films showing room temperature ferromagnetism

2005 ◽  
Vol 133 (3) ◽  
pp. 177-182 ◽  
Author(s):  
Saki Sonoda ◽  
Yoshiyuki Yamamoto ◽  
Takahiko Sasaki ◽  
Ken-chi Suga ◽  
Koichi Kindo ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Local Electronic Structure ◽  
Mn Doped

Effect of Low Temperature Annealing on High Field Magnetoresistance and Hall effect in (Ga, Mn)As Dilute Magnetic Semiconductors

2004 ◽  
Vol 831 ◽  
Author(s):  
K. Ghosh ◽  
Mohammad Arif ◽  
T. Kehl ◽  
R. J. Patel ◽  
S. R. Mishra ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Low Temperature ◽  
High Field ◽  
Magnetic Semiconductors ◽  
Magnetic Semiconductor ◽  
Dilute Magnetic Semiconductors ◽  
Epitaxial Thin Films ◽  
Ferromagnetic Transition ◽  
Optimal Temperature ◽  
Low Temperature Annealing

ABSTRACTIn this paper we report the effect of low temperature annealing on the high field magnetotransport properties of epitaxial thin films of (Ga, Mn)As Dilute Magnetic Semiconductor (DMS) with low concentration (1.5 %) of Mn doping, which results in a ferromagnetic insulator. Annealing at an optimal temperature enhances the conductivity, carrier concentration, and ferromagnetic transition temperature. The field dependence of magnetoresistance is different below and above the ferromagnetic transition temperature. An attempt is made to analyze the data using a theoretical model proposed by Kaminski and Das Sarma [1].

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