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.

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.

Manganese-Doped CdGeAs2, ZnGeAs2 and ZnSiAs2 Chalcopyrites: A New Advanced Materials for Spintronics

2010 ◽  
Vol 168-169 ◽  
pp. 31-34 ◽  
Author(s):  
A.S. Morozov ◽  
L.A. Koroleva ◽  
D.M. Zashchirinskii ◽  
T.M. Khapaeva ◽  
S.F. Marenkin ◽  
...  
Keyword(s):  
Room Temperature ◽  
Magnetic Semiconductors ◽  
Dilute Magnetic Semiconductors ◽  
Charge Carriers ◽  
Advanced Materials ◽  
Temperature Dependences ◽  
P Type ◽  
Mn Doped ◽  
Curie Temperatures ◽  
Exchange And Superexchange Interactions

Based on the Mn-doped chalcopyrites CdGeAs2, ZnGeAs2 and ZnSiAs2, new dilute magnetic semiconductors with the p-type conductivity were produced. Magnetization, electrical resistivity and Hall effect of these compositions were studied. Their temperature dependences of magnetization are similar in form in spite of a complicated character, which is controlled by the concentration and mobility of the charge carriers. Thus, for T < 15 K, these curves are characteristic of superparamagnets and for T > 15 K, of a frustrated ferromagnet. In compounds with Zn these two states are diluted by a spinglass-like state. This specific feature is ascribed to attraction of Mn ions occupying neighboring sites and to competition between the carrier-mediated exchange and superexchange interactions. The Curie temperatures of these compounds are above room temperature. These are the highest Curie temperatures in the AIIBIVCV2:Mn systems.

DILUTED MAGNETIC SEMICONDUCTOR NANOWIRES

NANO ◽  
2008 ◽  
Vol 03 (01) ◽  
pp. 1-19 ◽  
Author(s):  
HEON-JIN CHOI ◽  
HAN-KYU SEONG ◽  
UNGKIL KIM
Keyword(s):  
Room Temperature ◽  
Diluted Magnetic Semiconductors ◽  
Magnetic Semiconductors ◽  
Diluted Magnetic Semiconductor ◽  
Room Temperature Ferromagnetism ◽  
Magnetic Semiconductor ◽  
Building Blocks ◽  
Free Standing ◽  
Diluted Magnetic ◽  
Mn Doped

An idea for simultaneously manipulating spin and charge in a single semiconductor medium has resulted in the development of diluted magnetic semiconductors (DMSs), which exhibits surprisingly room temperature ferromagnetic signatures despite having controversial ferromagnetic origin. However, achievement of truly room temperature ferromagnetism by carrier mediation is still the subject of intense research to develop the practical spin-based devices. Nanowires with one-dimensional nanostructure, which offers thermodynamically stable features and typically single crystalline and defect free, have a number of advantages over thin films with respect to studying ferromagnetism in DMSs. This review focuses primarily on our works on GaN -based DMS nanowires, i.e., Mn -doped GaN , Mn -doped AlGaN and Cu -doped GaN nanowires. These DMS nanowires have room temperature ferromagnetism by the local magnetic moment of doping elements that are in a divalent state and in tetrahedral coordination, thus substituting Ga in the wurtzite-type network structure of host materials. Importantly, our evidences indicate that the magnetism is originated from the ferromagnetic interaction driven by the carrier. These outcomes suggest that nanowires are ideal building blocks to address the magnetism in DMS due to their thermodynamic stability, single crystallinity, free of defects and free standing nature from substrate. Nanowires themselves are ideal building blocks for nanodevices and, thus, it would also be helpful in developing DMS-based spin devices.

scholarly journals Nano-Structured Dilute Magnetic Semiconductors for Efficient Spintronics at Room Temperature

2020 ◽  
Vol 6 (1) ◽  
pp. 15 ◽  
Author(s):  
Akanksha Gupta ◽  
Rui Zhang ◽  
Pramod Kumar ◽  
Vinod Kumar ◽  
Anup Kumar
Keyword(s):  
Magnetic Properties ◽  
Degrees Of Freedom ◽  
Room Temperature ◽  
Magnetic Semiconductors ◽  
Magnetic Semiconductor ◽  
Dilute Magnetic Semiconductors ◽  
Wide Band ◽  
Oxide Semiconductor ◽  
Antiferromagnetic Order ◽  
A Minor

In recent years, many efforts have been made to develop advanced metal oxide semiconductor nanomaterials with exotic magnetic properties for modern applications w.r.t traditional analogues. Dilute magnetic semiconductor oxides (DMSOs) are promising candidates for superior control over the charge and spin degrees of freedom. DMSOs are transparent, wide band gap materials with induced ferromagnetism in doping, with a minor percentage of magnetic 3d cation to create a long-range antiferromagnetic order. Although significant efforts have been carried out to achieve DMSO with ferromagnetic properties above room temperature, it is a great challenge that still exists. However, TiO2, SnO2, ZnO and In2O3 with wide band gaps of 3.2, 3.6, 3.2 and 2.92 eV, respectively, can host a broad range of dopants to generate various compositions. Interestingly, a reduction in the size of these binary oxides can induce ferromagnetism, even at room temperature, due to the grain boundary, presence of defects and oxygen vacancies. The present review provides a panorama of the structural analysis and magnetic properties of DMSOs based on binary metal oxides nanomaterials with various ferromagnetic or paramagnetic dopants, e.g., Co, V, Fe and Ni, which exhibit enhanced ferromagnetic behaviors at room temperature.

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

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

scholarly journals Synthesis and Characterization of Sodium Bis(2-ethylhexyl) Sulfonsuccinate (AOT) Capped Pure and Mn-Doped CdS Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
D. Venkatesan ◽  
D. Deepan ◽  
J. Ramkumar ◽  
S. Moorthy Babu ◽  
R. Dhanasekaran
Keyword(s):  
Thin Films ◽  
Magnetic Semiconductors ◽  
Dilute Magnetic Semiconductors ◽  
Transition Metal Ions ◽  
Hexagonal Structure ◽  
Cds Nanoparticles ◽  
Sem Images ◽  
Semiconducting Properties ◽  
Mn Doped

CdS nanoparticles and thin films are well known for their excellent semiconducting properties. When transition metal ions are doped into the CdS, it exhibits magnetic properties in addition to semiconducting properties and they are termed as dilute magnetic semiconductors (DMSs). In this paper, we discuss the preparation of sodium bis(2-ethylhexyl) sulfonsuccinate (AOT) capped CdS nanoparticles and thin films doped with magnetic impurity Mn. Sodium bis(2-ethulexyl) sulfonsuccinate (AOT), capping agent promotes the uniform formation of nanoparticles. Optical characterizations are made using the UV-Vis spectrometer, PL, and FTIR. XRD shows the hexagonal structure of the CdS. SEM images and EDS measurements were made for the thin films. EPR shows the clear hyperfine lines corresponding to Mn2+ion in the CdS nanoparticles.

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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