Magnetic Properties Of Pristine Research Articles

Adsorption of Hydrogen Molecules in Nickel Decorated Silicene

First-principles simulations based on density functional theory (DFT) have been used to study the structural, electronic and magnetic properties of pristine and Ni decorated silicene sheets. Generalized Gradient Approximation (GGA) based exchange correlation functionals are used under software package Quantum ESPRESSO (QE), 6.5 versions. We have reconstructed the optimized unit cell of silicene, which has a face centered cubic (fcc) structure with two silicon atoms having lattice parameters a = b = 3.8 Å. The distance between two nearest silicene monolayers is found to be 20.5 Å which is large enough to neglect the interlayer interactions between 4×4 supercells of silicene monolayers. The atoms in the prepared supercell are fully relaxed under Bloyden-Fletcher-Goldfarb-Shanno (BFGS) scheme prior to the self-consistent, band structure and density of state (DoS) calculations. The pristine silicene is semi-metallic in nature possessing a Dirac-cone as in graphene. The h-site adsorption is found to be the most stable adsorption site of nickel in silicene with the binding energy of 4.69 eV. The addition of nickel atom completely distorts the hexagonal structure of silicene destroying the Dirac cone and the system becomes slightly insulating from its semi-metallic nature. We then construct a 4×4 nickel dimer silicene which further destroys the hexagonal silicene structure with further opening of the band gap. The charge transfer analysis in the Ni decorated systems shows the charge transfers of 0.163e and 0.294e in Ni adatom silicene and Ni dimer silicene respectively showing that the nickel atoms are adsorbed by weak van der Waals forces in both of the systems. We then proceed to hydrogen molecule adsorption in these prepared 4×4 silicene systems: pristine, Ni adatom and Ni dimer silicene systems. The adsorption energy of hydrogen in the Ni adatom silicene is found to be the largest making it the most effective system for hydrogen storage.

Enhancement of electronic and magnetic properties in Cr2O3 monolayer honeycomb-kagome by hydrogenation and oxygenation

This study investigates the structural, electronic, and magnetic properties of pristine, hydrogenated, and oxygenated Cr2O3 monolayer honeycomb-kagome (HK) surface using first-principles calculations based on density functional theory (DFT). Molecular dynamics and phonon dispersion calculations demonstrate the thermal and dynamic stability of these systems, implying their feasibility for laboratory synthesis. The results revealed that the adsorption of hydrogen and oxygen atoms on the Cr2O3 monolayer surface exhibited negative adsorption energies, indicating that these structures are energetically favorable. Specifically, the adsorption of oxygen atoms transforms the initial half-metallic nature of the monolayer into semiconducting behavior. Moreover, the introduction of hydrogen and oxygen atoms considerably enhances the Curie temperature of the surface. These findings offer a practical approach for enhancing the electronic and magnetic properties of Cr2O3 monolayer HK surface, thereby facilitating their prospective application in spintronics.

Structural, Electronic & Magnetic Properties of Pristine and Defected ZnO Monolayer: First-Principles Study

Electronic and magnetic properties of materials are appealing properties and have budding applications in the devices. In this work, we have investigated the structural, electronic and magnetic properties of pristine Zinc-Oxide (ZnO) and Oxygen-defected Zinc-Oxide (ZnO_O) materials by spin-polarized density functional theory (DFT) method. Structural properties are studied by calculating their total ground state energy, and found that both are stable 2D materials. It is also found that ZnO have higher stability than of ZnO_O material. Electronic properties of considered materials are examined by analyzing of their band structure, density of states (DOS) calculations and found that ZnO is a direct band gap, n-type semiconductor material in its pristine form and an indirect band gap, p-type semiconductor material in its Oxygen-defected form (ZnO_O). Magnetic properties of pristine and defected ZnO are investigated by analyzing their density of states (DOS) and partial density of states (PDOS) calculations, they revealed that ZnO and ZnO_O have non-magnetic properties.

DFT+U study on the magnetic properties of 3d transition metal doped β borophene

Two-dimensional materials with strong magnetism have attracted extensive attention for their potential application in spintronics. Recently, thess β 12 borophene with stable structure has been successfully synthesized experimentally. However, the β 12 borophene with non-magnetism limits its application in spintronics. The structural, electronic and magnetic properties of pristine and 3d transition metal (TM)-doped β 12 borophene monolayers are studied by means of first-principles calculations based on the GGA + U approach. Our results indicate that the doping of the Ti-, V-, Cr-, Mn-, Fe-, Co- and Ni atoms can induce magnetism in β 12 borophene and comparatively large magnetism can be obtained in Cr-, Mn-, Fe- and Co-doped systems. The Cr-, Mn- and Co-doped β 12 borophene exhibit antiferromagnetic ground states, while ferromagnetic ground state occurs in the Fe-doped system. Particularly, the spin density distribution of the Cr- and Mn-doped β 12 borophene is highly localized, which have a promise for application in magnetic storage devices. Our work provides a valuable theoretical guidance for the further experimental study and application of borophene materials in spintronics. • The doping of the Ti-, V-, Cr-, Mn-, Fe-, Co- and Ni atoms can induce magnetism in β 12 borophene and comparatively large magnetism can be obtained in Cr-, Mn-, Fe- and Co-doped systems. • The Cr-, Mn- and Co-doped β 12 borophene systems exhibit antiferromagnetic ground states, while ferromagnetic ground state occurs in the Fe-doped system. • The spin density distribution of the Cr- and Mn-doped β 12 borophene is highly localized, which have a promise for application in magnetic storage systems.

Effect of nickel impurity on structural, magnetic and electronic properties of WX2MLs (X = S, Se): An ab-initio study

We have studied the spin dependent structural, electronic and magnetic properties of pristine and Ni doped WX2 (X = S, Se) 2D monolayers by using density functional theory (DFT). The doping process improves and control the electronic and magnetic properties of TMDCs which is essential for application in electronics, optoelectronics and spintronics. WX2MLs with Ni impurity shows ferromagnetic behaviour. Spin resolved energy band gap have been observed. The Ni doped WSe2 exhibits the characteristics of half metal with 0.88 (D) and 0.02 (D) eV energy band gap for up and down spin respectively. The WS2ML with Nickel impurity shows 1.03 (I) and 0.17 (D) eV energy band gap for up and down spin respectively. The total magnetic moment of both Ni doped WX2MLs is found to be approximately 4µB which is due to local effect of the dopant. The exclusive combination of magnetic response and narrow bandgap which expedite the application of spintronics and yields magnetic semiconductors.

Functionalization of an ionic honeycomb KF monolayer via doping.

Doping has been widely employed to functionalize two-dimensional (2D) materials because of its effectiveness and simplicity. In this work, the electronic and magnetic properties of pristine and doped KF monolayers are investigated using first-principles calculations based on density functional theory (DFT). Phonon dispersion curves and ab initio molecular dynamics (AIMD) snapshots indicate good stability of the pristine material. The band structure shows an insulating behavior of the KF monolayer, with indirect gaps of 4.80 (6.53) eV as determined using the PBE (HSE06) functional. Its ionic character is also confirmed by the valence charge distribution and Bader charge analysis, and is generated by charge transfer from the K-4s orbital to the F-2p orbital. Doping at both anion and cation sites is explored using N/O and Ca/Sr as dopants, respectively, due to their dissimilar valence electronic configuration in comparison with that of the host atoms. It is found that the KF monolayer is significantly magnetized, where total magnetic moments of 2.00 and 1.00 μB are obtained via N and O/Ca/Sr doping, respectively. Moreover, the appearance of new middle-gap energy states leads to the development of a magnetic semiconductor nature, which is regulated by N-2p, O-2p, Ca-3d, Ca-4s, Sr-4d, and Sr-5s orbitals. Further investigation of codoping indicates that a magnetic-semiconductor nature is preserved, where the synergistic effects of dopants play a key role in the electronic and magnetic properties of the codoped systems. The results presented herein introduce doping as an efficient approach to functionalize the ionic KF monolayer to obtain prospective d0 spintronic materials, a functionality that is not accounted for by the pristine monolayer.

Doping-mediated electronic and magnetic properties of graphene-like ionic NaX (X = F and Cl) monolayers.

In this work, the stability, and electronic and magnetic properties of pristine and doped graphene-like ionic NaX (X = F and Cl) monolayers are explored using first-principles calculations. The good stability of NaF and NaCl monolayers is confirmed by phonon dispersion curves and ab initio molecular dynamics simulations. Electronic structure calculations show their insulator nature with large indirect band gaps of 5.43 (7.26) and 5.06 (6.32) eV as calculated with the PBE (HSE06) functional, respectively. In addition, their ionic character is also demonstrated. Furthermore, a doping approach is explored to functionalize NaX monolayers for spintronic applications. For such a goal, IIA- and VIA-group atoms are selected as dopants due to their dissimilar valence electronic configuration as compared with the host atoms. The results indicate the emergence of magnetic semiconductor nature with a total magnetic moment of 1μB. Herein, magnetic properties are produced mainly by the dopant atoms, which induce new middle-gap energy states around the Fermi level. Finally, the effects of codoping the NaF monolayer with Ca and O and NaCl with Ba and O are also examined. Adjacent Ca-O and Ba-O pairs preserve the non-magnetic nature. Further separating dopants leads to the emergence of magnetic semiconductor behavior, with lower magnetization than separate doping. This work introduces new ionic 2D materials for optoelectronic and spintronic applications, contributing to the research effort to find out new 2D multifunctional materials.

Electronic structure and magnetism of pristine, defected, and strained Ti2N MXene

From first principles electronic structure calculations, we unravel the evolution of structural, electronic, and magnetic properties of pristine, defected, and strained titanium nitride MXene with different functional groups (-F, -O, -H, and -OH). The formation and cohesive energies reveal their chemical stability. The dynamical stability of Ti2N mono-layer is also confirmed by phonon calculations. The MAX phase and defect free functionalized MXenes are metallic except for oxygen terminated (Ti2NO2) one which is 100% spin polarized half-metallic ferromagnet. The spin–orbit coupling significantly influences the bare MXene (Ti2N) to exhibit Dirac topology and band inversion near the high symmetry directions. The strain effect sways the Fermi level thereby shifting it towards lower energy state under compression and towards higher energy state under tensile strain in Ti2NH2. The Ti2NO2 exhibits exotic electronic structure not only in pristine but also in strained and defected structures. Its half-metallic nature changes to semi-metallic under 1% compression and it is completely destroyed under 2% compression. In single vacancy defect, its band structure remarkably transforms from half-metallic to semi-conducting with large band gap in 12.5% Ti, weakly semi-conducting in 5.5% Ti, and semi-metallic in 12.5% O. The 25% N defect changes its half-metallic characteristic to metallic. Further, the 12.5% Co substitution preserves its half-metallic character, whereas Mn substitution allows it to convert half-metallic characteristic into weak semi-metallic characteristic preserving ferromagnetism. However, Cr substitution converts half-metallic ferromagnetic state to half-metallic anti-ferromagnetic state. The understanding made here on collective structural stability, and electronic band structure, and magnetic phenomena in novel 2D Ti2N derived MXenes open up their possibility in designing them for synthesis.

Modifying electronic and magnetic properties of the β-Sb monolayer by doping with III-, IV-, and V-group atoms

In this work, the structural, electronic, and magnetic properties of pristine and doped β-antimonene (Sb) monolayer have been investigated using first-principles calculations. Pristine β-Sb single layer has an indirect energy gap of 1.26 eV. As dopants, some III-(B, Al, and Ga), IV-(C, Si, and Ge), and V-group (N, P, and As) atoms are considered. Due to the modified electronic interactions and difference in atomic size, substitutional incorporation of foreign atoms causes a local structural distortion, which is reflected on some structural parameters including bond length, buckling height, and interatomic angle. III- and V-group dopants tune the electronic band gap of β-Sb monolayer, preserving its non magnetic nature. Meanwhile, magnetic semiconductor behavior is induced by doping with IV-group atoms, where dopants are the main contributor to the magnetic properties. Results presented herein propose efficient approaches to modify the fundamental properties of β-Sb monolayer as well as induce new features in order to make it more suitable for spintronic and optoelectronic applications.

Structural, Third Order Nonlinear and magnetic properties of pristine and Ni-doped CuO nanoparticles: Diluted magnetic semiconductors

Ni-doped Copper Oxide nanostructures have been synthesized using the modified auto-combustion method. The structural, morphological, vibrational, linear, and nonlinear optical properties were examined. XRD pattern revealed that the samples exhibited a monoclinic structure having a space group C2/c. Origin of adsorbed oxygen and bivalent state of Cu and Ni were revealed from XPS analysis. HRTEM and FEG-SEM images with EDAX spectra confirmed the formation of spherical particles with smooth surfaces and also validated the purity of synthesized nanostructures. The magnetic measurements confirmed the nanoscale doping of Ni specifically from the superparamagnetic behaviors. The characteristic vibrational modes of CuO were identified from the vibrational analysis. The red-shifted Raman mode with broadening indicates the formation of disorders and size effects. The UV-Visible spectrum showed a decreasing trend in bandgap with an increment in nickel concentration, corresponding to the presence of intra-band defect/imperfection states. Emission peaks obtained from room temperature photoluminescent spectrum indicated the presence of defects in the nanostructures. Third-order nonlinear optical properties, measured via, the Z-scan method with the help of a continuous wave (CW) laser and an enhancement in the nonlinear optical parameters were observed on doping. Hence it confirmed that the prepared nanostructures can be used for various optoelectronic applications.

Structural, optical, and magnetic properties of pristine and Cr doped WO3 nanoparticles

WO3 nanoparticles doped with chromium were prepared via acid-assisted precipitation method. These nanoparticles were characterized by XRD, FTIR, Raman, UV-DRS, SEM-EDS and photoluminescence (PL) spectral techniques. The XRD peaks confirmed the monoclinic arrangement with decrease in crystallite size on increasing the dopant concentration. The surface characterizations exposed the doping of chromium ions within the host lattices of WO3. From the SEM images, it can be noticed that doping changes the morphology of WO3 nanoparticles. The structure and crystal quality were studied by FTIR and Raman spectra. The absorption spectra reveals that the optical band gap energy is reduced after doping and there is rise in Urbach energies on increasing the Cr concentration. The PL spectra give an insight of increasing numbers of oxygen vacancies in WO3 after doping. The M–H hysteresis loops reveal that the ferromagnetic character is enhanced on low dopant concentration while at higher dopant concentrations, antiferromagnetism (FM) dominates.

Electronic and magnetic properties in nitrogen-doped 2D titanium carbides (MXenes): Insight from first-principles calculations

First-principles computations were performed to investigate the electronic and magnetic properties of pristine and nitrogen (N)-doped Ti2C and Ti3C2 MXenes. The effects of the concentrations and the distributions of nitrogen were considered. Our results show that N doping can enhance the conductivity of Ti2C and Ti3C2 MXenes, which both present metallic character under different N concentration. The metallicity of N-doped Ti2C and Ti3C2 MXenes indicates potential in metal-ion batteries. Also, N doping leads to an antiferromagnetic (AFM)-ferromagnetic (FM) transition for Ti3C2. The critical concentration from AFM to FM configurations is between 25% and 50%. Importantly, the magnetic state of the N-doped Ti3C2 monolayers is related with the N distribution. However, Ti2C systems maintain an AFM state regardless of N concentrations or N distributions. Thus, based on the basic understanding of the N-doped Ti2C and Ti3C2 monolayer, we believe that our findings would provide theoretical support for the multifaceted application of the C-based MXenes.

Synthesis and characterization of catalytic CVD growth pristine and functionalized MWCNT

The catalyzed CVD method is considered significant for the production of low cost and high yield carbon nanostructures. In this study, multiwall carbon nanotubes (MWCNTs) were synthesized using a facile and efficient way with the modified CVD method, using Co nanoparticles as the metallic catalysis for MWCNT growth, in a distinct temperature range of 650–750 °C. The structural and magnetic properties of pristine and functionalized MWCNT (p-MWCNT and f-MWCNT) are investigated in the temperature range of 10–300 K. The phase structure of all MWCNT samples was analyzed using various characterization techniques, namely, x-ray diffraction, Raman, and x-ray photoelectron spectroscopy. Scanning electron microscopy and particle size analysis suggested that the diameter of MWCNTs increases with a rise in the growth temperature, but the nanotube density decreases at 750 °C. Temperature-dependent magnetization studies of the p-MWCNT and f-MWCNT samples were investigated using a quantum design physical property measurement system-vibrating sample magnetometer mode. The magnetic properties and the effect of the growth temperature and acid functionalization on the morphology of MWCNT were also investigated. The results revealed that the diamagnetism effect of the graphitic nanotubes is dominating for p-MWCNT, and it reduces for f-MWCNT. A possible explanation for this feature is discussed in detail in the later part of this article. It may be considered that this study, which emerged with different growth temperatures of MWCNTs using a facile method for gaining control over magnetic properties, can be fundamental for further consideration of magnetic MWCNTs for various potential applications.

Investigating potential properties of (8,0) Silicon Carbide Nanotube for applications in band gap tuning

The changes in electronic and Magnetic properties of spin polarized silicon carbide nanotube (SiCNT), investigated using density functional theory and Quantum-Espresso computational package. In the present work, the electronic and magnetic properties of pristine, vacancy and transition metal(TM) doped (8,0) SWSiCNT are systematically investigated to give a detailed understanding of these materials. Magnetic moment were calculated, the electronic properties of zigzag (8,0) semiconductor silicon carbide nanotubes (SiCNTs) doped once at the time with Iron, Cobalt, Mnganse, Gadolinium and Hafinime. We have looked at the two possible scenarios where the guest atom X (Fe, Co, Mn, Gd, Hf), substituting in the Site of the Silicon atom X Si and carbon atom X C with different concentration, in the unit cell. We found that in the case of one atom Fe doped SiCNT, Co doped SiCNT, Mn doped SiCNT, Gd doped SiCNT and Hf doped SiCNT replacing a Silicon atom position annotated by Fe Si exhibits a magnetic moment of 1.99 μ B /cell and Mn Si exhibits a magnetic moment of 0.98 μ B /cell, Co Si exhibits a magnetic moment of 0.02 μ B /cell, whereas, in the case of two atom 2Fe doped SiCNT, 2Co doped SiCNT, 2Mn doped SiCNT, Gd doped SiCNT and Hf doped SiCNT replacing at two carbon atom position annotated by Fe Si exhibits a magnetic moment of 3.98 μ B /cell and Mn Si exhibits a magnetic moment of 1.99 μ B /cell, Also, two atom Cobalt replacing carbon, (CoC), induce a magnetic moment of 5.13 μ B and for three atom cobalt replacing Carbon 5.36. Substitution of three Cobalt in site of Silicon gives the maximum magnetic moment 9.00 μ B /cell but in contrast the calculated results show that the Co doping in Silicon carbide nanotube induces the ferromagnetism and metallic property for all concentrations.The calculated results show that the Mn doping in Silicon carbide nanotube induces the ferromagnetism and originates a half metallic (HM) gap at Fermi level (EF)in minority spin channel (MIC) for for 3.125 %, 6.25%, 9.37% and 12.75% concentrations. Moreover, the calculated results show that the Fe doping in Silicon carbide nanotube induces the ferromagnetism and Half Metalic property for 3.125%, 6.25% and 9.37% concentrations. Doping concentrations and dopant positions regulate the electronic structure and Magnetic property of the Silicon carbide nanotube, exhibiting both semiconducting and half-metallic behaviours as a response to the concentration of Transition Metals.

Site-substitution effect on skyrmion phases of Cd2+-Cu2OSeO3 nanocrystallites

The past decade has seen a significant uptick in research interest to study the materials that can host magnetic skyrmion lattices. The curiosity of such materials is mainly driven by the technological applications of emergent skyrmion lattices that manifest a whirlpool-like spins arrangement. Insulating Cu2OSeO3 reported to host magnetic skyrmion lattices below 60 K and considered as a potential candidate for exploring this new phase of materials. Here in this article, we propose a new synthesis process to grow the Cd2+-substituted Cu2OSeO3 nanocrystallites with variable sizes ranging over 50–200 nm. The proposed method consists of only a single-step heat treatment of 12 h, which is cost-effectivethan the routine solid-state process that requires a rigorous 15–20 days of heat treatment. By employing X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), and isothermal magnetization (M-T) measurements, we present a comparative investigation of the structural, electronic and magnetic properties of pristine and Cd2+-substituted Cu2OSeO3 nanocrystallites. As non-magnetic substitution can alter the fundamental magnetic interactions, therefore, Cd2+-Cu2OSeO3 nanocrystallites offer a new methodology to control the magnetic skyrmion phases and its stability.

Defects and light elements (Li, Be, B, C, O and F) driven d0 magnetism in InN monolayer

We computed structural, electronic, and magnetic properties of pristine and both intrinsic/extrinsic point defects included InN monolayer. The stability of the pristine InN monolayer is confirmed through the phonon band dispersion. InN pristine monolayer exhibits an indirect bandgap, 0.61 eV between M and Γ high symmetry points. InV, NV, (In/N)V vacancies, and antisite defects such as In↔N are considered in InN monolayer, together with light elements, Li, Be, B, C O, and F doping at nitrogen (N) atomic site. We calculated the formation energies for understanding the stability of point defect included and doped InN monolayers. The NV included InN monolayer showed the most stable behaviour among structures. Vacancy defects InV, NV, and (In/N)V included monolayers showed 3.00 μB, 0.00 μB, and 2.00 μB magnetic moment, respectively. However, antisite defects included monolayers showed zero magnetic moment. Further, Be and C doped monolayers showed 0.91 μB and 1.09 μB magnetic moment, respectively, whereas the other dopants showed zero magnetic moment. Thus, the onset of magnetism can be realized in InN monolayer by inducing defects with a maximum of 3.00 μB for InV defects.

Tetragonal and uniaxial strains in pristine and doped half-Heusler AuMnSn alloy

Using the first-principles density functional theory calculations, we examined the effect of tetragonal strain (t-strain) and uniaxial strain (u-strain) on the electronic and magnetic properties of pristine and Sb-doped half-Heusler AuMnSn alloy. Our result shows that ferromagnetic half-Heusler AuMnSn (AMS) exhibits half metallic ferromagnetism (HMF) only from −8% to −10% u-strain. On the other hand, the Sb-doped half-Heusler AuMnSn (AMSS) exhibits HMF from −2% to 4% t-strain and from −4% to 2% u-strain while the width of the minority spin band gap remains unaltered. We also observed changes in the magnetic moments as the applied strain changes from compressive to tensile strain. Our result suggests the possibility of epitaxial growth of thin-film of half-metallic AMSS on a semiconductor substrate, even with a small lattice mismatch.

A density functional theory study on the interaction of toluene with transition metal decorated carbon nanotubes: a promising platform for early detection of lung cancer from human breath

In this study, single-wall carbon nanotubes (SWCNTs) decorated by platinum-group transition metals (Pt, Pd, Rh, or Ru) were introduced as promising nanosensors for the detection of toluene, an important biomarker in the exhaled breath of the lung cancer patients. First-principle calculations based on density functional theory (DFT) was employed to scrutinize the impact of an individual toluene gas molecule on the structural, electronic, and magnetic properties of pristine and metal decorated SWCNTs. It was discovered that toluene is physisorbed on the pristine SWCNT through the interaction of the π orbitals of the carbon atoms in the toluene and the nanotube. Decoration of the SWCNT with metal atoms enhanced the adsorption energies significantly by means of strong overlapping between d orbital of the metal atoms and p orbital of C atoms in the benzene ring of toluene. Investigations showed that toluene is strongly chemisorbed on Rh- and Ru-SWCNT systems via strong covalent bonds with the superior response (−96.98% and −99.98%, respectively), and moderately chemisorbed on Pt-SWCNTs (−27.3%) and Pd-SWCNTs (61.60%). Our findings propose metal decorated SWCNT molecular sensors are attractive candidates for the detection of toluene and other lung cancer biomarkers in the exhaled breath of the lung cancer patients.

Experimental and DFT investigation of electronic structure and ferromagnetic stable state in pristine and Mn: SnO2 NPs

We have investigated the electronic and magnetic properties of pristine and Mn (6%) doped SnO2 nanoparticles (NPs). Rietveld refinement of XRD affirmed the single-phase rutile structure with P42/mnm space group. The magnetic measurements at RT elucidated that pristine SnO2 is nonmagnetic, whereas the Mn-doped sample has ferromagnetic (FM) and simultaneously paramagnetic (PM) independent phases. For tracing the possible sources of the FM signal, density functional theory (DFT) calculations at generalized gradients approximation (GGA) were employed. DFT findings predicted that the presence of Ov solely without Mn dopant ions is an insufficient condition to produce stable magnetic order in pristine SnO2. Thus, the d0 ferromagnetic in stoichiometric SnO2 can be excluded. Furthermore, Mn (6.25%): SnO2 system (Sn15MnO32) without OV is nonmagnetic, but with the presence of Ov the system exhibited FM stable state. Our study demonstrated that the Mn 3d and O 2p electronic states showed a strong hybridization at Fermi level (EF) and the local magnetic moment is found to be arising from spontaneous spin-polarized of Mn 3d states near Fermi EF with 3.2 μB/Mn moments. The most sensible percolation mechanism behind the spin-split impurity band and the FM response has been discussed.

Structural, Optical and Magnetic Properties of Pristine, (Mn, Al) co-doped ZnO Nanocrystallites Synthesized via co-Precipitation Method

Undoped and (Mn, Al) co-doped Zinc Oxide nanoparticles are synthesized by chemical co-precipitation method at room temperature effectively via poly ethylene glycol (PEG) as stabilizing agent. XRD data reveals that all the concentrations acquire hexagonal wurtzite crystal structure with no secondary peaks concerning to Al or Mn, indicating successful dissolution of Al and Mn in to ZnO host lattice. The exact particle size is estimated using TEM illustrations, which is confirmed through the XRD results. EDS spectrum shows, no impurities are present in the samples other than manganese and aluminum. The absorption spectra of all the samples reveal characteristic absorption edge in the vicinity of 375 nm. PL spectra show that all the concentrations include defect associated peaks in the visible region. VSM measurements reveal the ferromagnetic nature for co-doped samples. Copyright © VBRI Press.