Silicon Sites Research Articles

Computationally Driven Discovery of T Center-like Quantum Defects in Silicon.

Quantum technologies would benefit from the development of high-performance quantum defects acting as single-photon emitters or spin-photon interfaces. Finding such a quantum defect in silicon is especially appealing in view of its favorable spin bath and high processability. While some color centers in silicon have been emerging in quantum applications, there remains a need to search for and develop new high-performance quantum emitters. By searching a high-throughput computational database of more than 22,000 charged complex defects in silicon, we identify a series of defects formed by a group III element combined with carbon ((A-C)Si with A = B, Al, Ga, In, Tl) and substituting on a silicon site. These defects are analogous structurally, electronically, and chemically to the well-known T center in silicon ((C-C-H)Si), and their optical properties are mainly driven by an unpaired electron on the carbon p orbital. They all emit in the telecom, and some of these color centers show improved properties compared to the T center in terms of computed radiative lifetime, emission efficiency, or smaller optical linewidth. The kinetic barrier computations and previous experimental evidence show that these T center-like defects can be formed through the capture of a diffusing carbon by a substitutional group III atom. We also show that the synthesis of hydrogenated T center-like defects followed by a dehydrogenation annealing step could facilitate the formation of these defects. Our work motivates further studies on the synthesis and control of this new family of quantum defects and demonstrates the use of high-throughput computational screening to discover new color center candidates.

Unmasking Fluorinated Moieties on the Surface of Hydride-Terminated Silicon Nanoparticles.

Despite the widespread use of hydrofluoric acid (HF) in the preparation of silicon surfaces, the true nature of fluorinated surface species remains unclear. Here, we employ an array of characterization techniques led by solid-state nuclear magnetic resonance spectroscopy to uncover the nature of fluorinated moieties on the surface of hydride-terminated silicon nanoparticles (H-SiNPs). A structural model that explains the observed trends in 19F and 29Si magnetic shielding is proposed and further supported by quantum chemical computations. Fluorine is incorporated into local oxidation domains on the surface and clustered at the interface of the oxide and surrounding hydride-terminated surface. Silicon sites capped by a single fluorine are also identified by their distinct 19F and 29Si chemical shifts, providing insight into how fluorine termination influences the electronic structure. The extent of fluorine passivation and the effects of fluorine on the optical properties of SiNPs are also discussed. Finally, challenges associated with Teflon contamination are highlighted that future explorations of nanomaterials may have to contend with.

An evaluation of pyrite as a component of respirable coal dust

Over the past two decades, the rise in coal worker’s pneumoconiosis has prompted research into the effects of respirable coal dust components. This study explores how coal-pyrites produce hydroxyl radicals (•OH), a reactive oxygen species closely associated with particle toxicity, and assesses the ability of safe chemical additives to reduce •OH production at various pH levels. Promising candidates were evaluated in various solutions, including tap and process waters and simulated lung fluid. We employed electrokinetic measurements, infrared and X-ray photoelectron spectroscopies, and ab initio atomistic simulations to analyze particle surfaces. The study also looked at how surface aging affects •OH production. Our results show that •OH generation of the pyrite varies and is catalyzed by elements like silicon, aluminum, and iron in pyrite. Carboxymethyl cellulose was effective in reducing •OH production by targeting surface sulfide and silicon sites and affecting surface hydration and charge. Atmospheric aging was found to increase •OH production, especially in the pyrite with high iron and silicon and low calcium contents, relative to other samples. This highlights the role of the pyrite surface properties and chemical composition, and the solution pH and composition in •OH generation by coal-pyrites.

Syntheses and Conformations of a Trinuclear Gold(I) System Based on a Triethinyl‐trisilacyclohexane Scaffold

AbstractTrisilacyclohexanes and bissilylmethanes with acetylene units attached to silicon sites have been converted into tri‐ and di‐nuclear gold(I)phosphane complexes and characterized by NMR spectroscopy and X‐ray diffraction. The bissilylmethane‐based gold complexes were used as a test system to work out the synthetic routes before transferring them to the trisilacyclohexane scaffolds, because the latter are more difficult to access. The occurrence of aurophilic interactions (short Au ⋅ ⋅ ⋅ Au contacts) depends on the steric bulk of the phosphorus‐bonded alkyl and aryl groups. DFT studies show that dispersion effects play an important role in the ability to form intramolecular Au ⋅ ⋅ ⋅ Au interactions. QTAIM analyses show that a subtle change of the steric bulk of the phosphane groups alters the relative strength of the dispersion and aurophilic interactions. The combination of DFT studies and X‐ray diffraction experiments shows that the conformation of the trisilacyclohexane backbone is also phase dependent.

Annealing-induced defects and optical degradation in sputter-deposited silicon nitride: Implications for photonic applications

Silicon nitride (SiNx) is a critical material for advanced photonic applications. This study investigates the effect of annealing on sputter-deposited silicon nitride. The results demonstrate that blisters and holes appear in annealed SiNx, which compromise its integrity and lead to increased roughness. These defects are closely related to the annealing process. Specifically, the blister diameter expands from 5.17 μm at 600 °C to more than 25 μm at 800 °C. Additionally, the defect ratio increases significantly from 1.25 % to 14.82 % for full annealing. Rapid thermal annealing induces a 12 % defect ratio and a surface roughness of 13.1 nm. X-ray photoelectron spectroscopy results suggest that defects originate from unsaturated silicon sites, particularly in silicon-rich SiNx. Raman spectroscopy reveals a blueshift in the silicon peak after annealing, indicating biaxial tensile stress applied to the coatings, which is supported by the diffraction peaks observed in grazing incidence X-ray diffraction patterns. This mechanical stress may contribute to blistering and bursting. Moreover, annealing significantly alters the refractive index and dispersion properties of SiNx, with transmission losses reaching up to 20 %, presenting a considerable challenge for photonic applications. Notably, the performance of silicon nitride-based Bragg reflectors deteriorates markedly after annealing. This study elucidates the balance between annealing conditions and their effects on sputter-deposited silicon nitride, ensuring its continued viability in the rapidly expanding field of photonics.

Superexchange coupling of donor qubits in silicon

Atomic engineering in a solid-state material has the potential to functionalize the host with novel phenomena. STM-based lithographic techniques have enabled the placement of individual phosphorus atoms at selective lattice sites of silicon with atomic precision. Here we show that by placing four phosphorus donors spaced 10–15 nm apart from their neighbors in a linear chain, one can realize coherent spin coupling between the end dopants of the chain, analogous to the superexchange interaction in magnetic materials. Since phosphorus atoms are a promising building block of a silicon quantum computer, this enables spin coupling between their bound electrons beyond nearest neighbors, allowing the qubits to be separated by 30–45 nm. The added flexibility in architecture brought about by this long-range coupling not only reduces gate densities but can also reduce correlated noise between qubits from local noise sources that are detrimental to error-correction codes. We base our calculations on a full-configuration-interaction technique in the atomistic tight-binding basis, solving the four-electron problem exactly, over a domain of a million silicon atoms. Our calculations show that superexchange can be tuned electrically through gate voltages where it is less sensitive to charge noise and donor-placement errors. Published by the American Physical Society 2024

Crystalline phase transition in as-synthesized pure silica zeolite RTH containing tetra-alkyl phosphonium as organic structure directing agent

Two distinct RTH phases are formed through the bonding of fluoride to different silicon sites and this is controlled by adjusting the synthesis conditions.

Parameters Synthesis of Na-Magadiite Materials for Water Treatment and Removal of Basic Blue-41: Properties and Single-Batch Design Adsorber

Na-magadiite materials were prepared from a gel containing a silica source, sodium hydroxide, and water via hydrothermal treatment at different temperatures (130 °C to 170 °C) and periods of time (1 day to 10 days). In this study, four silica sources were selected (fumed silica, colloidal silica, Ludox HS-40%, and Ludox AS-40%). Variable conditions such as sodium hydroxide and water contents were explored at a specific temperature and reaction time. The obtained materials were characterized by using X-ray diffraction (XRD), thermogravimetry differential thermal analysis TG-DTA, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), Fourier Transform Infrared spectroscopy (FTIR), solid 29Si magic angle spinning magnetic nuclear resonance (MAS MNR, and nitrogen adsorption isotherms. A pure Na-magadiite phase was obtained from the four silica sources at a synthesis temperature of 150 °C after a period of one to two days with a characteristic basal spacing of 1.54 nm. At a longer reaction time of 3 days and a higher temperature of 170 °C, Na-kenyaite with a basal spacing of 2.01 nm was achieved, in addition to a quartz phase. The content of water or sodium hydroxide in the gel affected the nature of the prepared phases. A cauliflower-like morphology was obtained from colloidal silica sources, while a different morphology was achieved using solid fumed silica. The 29Si solid NMR confirmed the presence of Q3 and Q4 silicon sites in the Na-magadiite materials. The optimal Na-magadiite materials at 150 °C for 2 days were assessed for their ability to remove Basic Blue-41 dye from artificially contaminated aqueous solution. The Langmuir equation was used to estimate the maximum removal capacity. A maximum removal capacity of 219 mg/g was achieved using Na-magadiite prepared from a Ludox-HS40% silica source, and a maximum removal capacity of 167 mg/g was observed for Na-magadiite prepared from fumed silica. Basic Blue-4’s removal percentage was enhanced at basic pH levels (8 to 10) to a maximum of 95%. These materials could be regenerated for seven cycles of reuse with a reduction of 27 to 40% of the original values. Therefore, Na-magadiite materials are promising and efficient removal agents for the removal of Basic Blue-41 from effluents.

Active sites of Te-hyperdoped silicon by hard x-ray photoelectron spectroscopy

Multiple dopant configurations of Te impurities in close vicinity in silicon are investigated using photoelectron spectroscopy, photoelectron diffraction, and Bloch wave calculations. The samples are prepared by ion implantation followed by pulsed laser annealing. The dopant concentration is variable and high above the solubility limit of Te in silicon. The configurations in question are distinguished from isolated Te impurities by a strong chemical core level shift. While Te clusters are found to form only in very small concentrations, multi-Te configurations of type dimer or up to four Te ions surrounding a vacancy are clearly identified. For these configurations, a substitutional site location of Te is found to match the data best in all cases. For isolated Te ions, this matches the expectations. For multi-Te configurations, the results contribute to understanding the exceptional activation of free charge carriers in hyperdoping of chalcogens in silicon.

Spectroscopic studies of heavy metal cations influence on the structure of synthetic hydrated calcium aluminosilicates.

Calcium aluminosilicate hydrates (C-(A)-S-H) with two different C/S molar ratios of 1.0 and 1.7 were synthesized by precipitation with the use of the alkali-activation method. The samples were synthesized with solutions of heavy metals nitrates such as nickel (Ni), chromium (Cr), cobalt (Co), lead (Pb), and zinc (Zn). Metal cations were added in the amount of Ca:Me equal to 9:1, while Al/Si was 0.05. The influence of the addition of heavy metal cations on the structure of the C-(A-)S-H phase was investigated. For this purpose, XRD was used to examine the phase composition of the samples, FT-IR and Raman spectroscopy were used to determine the effect of heavy metal cations on the structure of the obtained C-(A)-S-H phase and their degree of polymerization. Using SEM and TEM, changes in the morphology of the obtained materials were determined. Possible mechanisms of immobilization of heavy metal cations have been determined. It was found that some heavy metals (Ni, Zn, and Cr) could be immobilized by precipitation of insoluble compounds. On the other hand, they could remove Ca2+ ions from the structure of aluminosilicate and take their place, as evidenced by the crystallization of Ca(OH)2 in samples with the addition of Cd, but also Ni and Zn in small amounts. A third possibility is the incorporation of heavy metal cations at the silicon and/or aluminum tetrahedral sites, as is the case with Zn.

Xenon ion implantation induced defects and amorphization in 4H–SiC: Insights from MD simulation and Raman spectroscopy characterization

Xenon Focused Ion Beam (Xe-FIB) processing of 4H–SiC is an emerging technique with great potential for various applications. In this study, we investigate the evolution mechanism of damage caused by xenon ion implantation in 4H–SiC using a combination of molecular dynamics (MD) simulation and Raman spectroscopy. The study explores the microscopic mechanisms of damage processing and repairs using the proper potential function and the optimized simulation model. The MD simulation reveals that the vacancy and interstitial sites of silicon and carbon atoms, as identified by the Wigner-Seitz defect method, increase linearly with implanted dose until the dose reaches 2 × 1014 ions/cm2. Subsequently, the growth rate of each defect site in the damaged area slows down and eventually comes to a saturation state with a continuous increase in dose. The growth rate of the amorphous region also slows down with the constant increase in dose, similar to the results obtained through variable temperature Raman spectroscopy characterization experiments on 4H–SiC (0001) nitrogen-doped substrates implanted with different doses of xenon ions. Furthermore, unlike light ions such as hydrogen and helium, Xe ions cause significant damage to the inside of 4H–SiC, resulting in the inability to produce structurally complete silicon vacancy defects. Our findings provide insights into the fundamental mechanism of Xe-FIB processing and have implications for future applications in semiconductor technology.

Silicon pools, fluxes and the potential benefits of a silicon soil amendment in a nitrogen-enriched tidal marsh restoration

Tidal marshes are important sites of silicon (Si) transformation, where dissolved Si (DSi) taken up by macrophytic vegetation and algal species is converted to biogenic silica (BSi), which can accumulate in the soil, be recycled within the marsh, or be exported to adjacent coastal waters. The role of restored and created tidal marshes in these processes is not well understood, nor is the impact of nutrient enrichment at either the plant or ecosystem level. Here, Si fluxes were examined to develop a Si mass balance in a nitrogen (N)-enriched marsh created with fine-grained dredged material from the Chesapeake Bay, United States. In addition, the effectiveness of Si soil amendments to ameliorate the negative effects of excess nitrogen on Spartina alterniflora was examined through laboratory and field experiments. Silicon was exported to the estuary as DSi (49 g m−2 y−1) and BSi (35 g m−2y−1) in stoichiometric excess of nitrogen and phosphorus. Rapid recycling of Si within both marsh and the tidal creeks appeared to be important in the transformation of Si and export from the marsh. Enhanced macrophyte SiO2 tissue concentrations were observed in the field experiment, with end-of-season mean values of 2.20–2.69% SiO2 in controls and 2.49–3.24% SiO2 in amended plots, among the highest reported for S. alterniflora; however, improved plant fitness was not detected in either experiment. Thus, tidal marshes created with a fine-grained, N-rich dredged material appear to function as a rich source of Si to the restored marsh and local estuarine environment, an overlooked ecosystem service. Soil Si amendments, however, did not appear likely to alleviate N-induced stress in S. alterniflora.

Epitaxially grown silicon-based single-atom catalyst for visible-light-driven syngas production

Improving the dispersion of active sites simultaneous with the efficient harvest of photons is a key priority for photocatalysis. Crystalline silicon is abundant on Earth and has a suitable bandgap. However, silicon-based photocatalysts combined with metal elements has proved challenging due to silicon’s rigid crystal structure and high formation energy. Here we report a solid-state chemistry that produces crystalline silicon with well-dispersed Co atoms. Isolated Co sites in silicon are obtained through the in-situ formation of CoSi2 intermediate nanodomains that function as seeds, leading to the production of Co-incorporating silicon nanocrystals at the CoSi2/Si epitaxial interface. As a result, cobalt-on-silicon single-atom catalysts achieve an external quantum efficiency of 10% for CO2-to-syngas conversion, with CO and H2 yields of 4.7 mol g(Co)−1 and 4.4 mol g(Co)−1, respectively. Moreover, the H2/CO ratio is tunable between 0.8 and 2. This photocatalyst also achieves a corresponding turnover number of 2 × 104 for visible-light-driven CO2 reduction over 6 h, which is over ten times higher than previously reported single-atom photocatalysts.

Mechanism of Selective Chlorination of Fe from Fe2SiO4 and FeV2O4 Based on Density Functional Theory

Vanadium slag is an important resource containing valuable elements such as Fe, V, Ti, and so on. A novel selective chlorination method for extracting these valuable elements from vanadium slag has been proposed recently. The proposed methods could recover valuable elements with a high recovery ratio and less of an environmental burden, while the study on the chlorination mechanism at the atom level was still insufficient. Fe2SiO4 and FeV2O4 are the two main phases of vanadium slag, and the iron element can be selectively extracted via the chlorination of NH4Cl. The NH4Cl decomposes into NH3 gas and HCl gas, which was the true chlorination agent. As a result, the chlorination reactions of Fe2SiO4 and FeV2O4 with HCl were firstly calculated using FactSage 8.0. Then, this paper studied the characteristics of HCl adsorption on the Fe2SiO4(010) surface and the FeV2O4(001) Fe-terminated surface mechanism of the selective chlorination of Fe from Fe2SiO4 and FeV2O4 via DFT calculations. The processes of chlorination of Fe2SiO4 and FeV2O4 involved the processes of removing O atoms from them with HCl gas. The iron in Fe2SiO4 was selectively chlorinated because HCl could adsorb on the iron site but could not adsorb on the silicon site. The iron in FeV2O4 was selectively chlorinated because the electronegativity gap between V and O was more significant than that between the Fe and O elements.

Atomic-Level Structure of Zinc-Modified Cementitious Calcium Silicate Hydrate.

It has recently been demonstrated that the addition of zinc can enhance the mechanical strength of tricalcium silicates (C3S) upon hydration, but the structure of the main hydration product of cement, calcium silicate hydrate (C-S-H), in zinc-modified formulations remains unresolved. Here, we combine 29Si DNP-enhanced solid-state nuclear magnetic resonance (NMR), density functional theory (DFT)-based chemical shift computations, and molecular dynamics (MD) modeling to determine the atomic-level structure of zinc-modified C-S-H. The structure contains two main new silicon species (Q(1,Zn) and Q(2p,Zn)) where zinc substitutes Q(1) silicon species in dimers and bridging Q(2b) silicon sites, respectively. Structures determined as a function of zinc content show that zinc promotes an increase in the dreierketten mean chain lengths.

Microstructural and 29Si and 27Al MAS NMR spectroscopic evaluations of alkali cation and curing effects on Class C fly ash-based geopolymer

The present paper investigates the effect of the alkali cation and curing conditions on the microstructure of Class C fly ash-based geopolymer using 27 Al and 29 Si MAS NMR spectroscopy. 27 Al and 29 Si MAS NMR spectroscopy has been utilized to characterize the geopolymer with a different alkaline activator (Na and/or K) and curing at different condition temperatures (25, 40 and 70°C) and oven curing time (8, 12 and 24h). Also, X-ray fluorescence spectrometer (XRF), X-ray diffraction (XRD), Fourier Transform Infrared (FT–IR) spectroscopy and Scanning electron microscope (SEM) were applied for the characterization of raw materials and samples. 29 Si MAS NMR chemical shift of different silicon sites revealed that the alkali cation, the oven curing time and temperature affect the microstructure of the formed material. The results showed that in KNa-based gels; the silica content in the gel is higher and the width of the 29Si MAS-NMR component line is reduced moderately which indicates that a more ordered phase has been formed.

Na2SO4 modified low-carbon cementitious binder containing commercial low-reactivity metakaolin for heavy metal immobilization: Mechanism of physical encapsulation and chemical binding

In this study, a Na2SO4 modified low-carbon cementitious binder based on commercial low-reactivity metakaolin (MK) and cement was utilized for the immobilization heavy metals (Cu2+, Ni2+, Cd2+ and Zn2+). The compressive strengths and leaching concentrations of the immobilization systems were investigated to evaluate the immobilization effect for heavy metals. Meanwhile, the pore structure and chemical compositions of the immobilization systems were characterized to study the immobilization mechanisms. Results demonstrate that the MK-blended systems exhibit excellent heavy metal immobilization effect and low releasing risk under the effect of Na2SO4. The incorporation of Na2SO4 significantly improve the compressive strength of the MK-blended systems due to the promotion effect on the early hydration kinetics of cement, the formation of ettringite and the pozzolanic reaction of MK. Moreover, the incorporation of Na2SO4 decreases the capillary porosity and/or increases the tortuosity of the MK-blended systems, which enhances the physical encapsulation to heavy metals. The MK-blended systems have higher chemical binding capacities to heavy metals than pure cement immobilization systems. This is due to the increase in the Si/Ca and Al/Ca atom ratios of calcium aluminosilicate hydrate that introduces more negative charged silicon and aluminium sites to bind heavy metal cations.

Orbital disorder and ordering in NaTiSi2O6 : Si29 and Na23 NMR study

${\mathrm{NaTiSi}}_{2}{\mathrm{O}}_{6}$ is an exemplary compound, showing an orbital assisted spin-Peierls phase transition at ${T}_{c}=210$ K. We present the results of $^{29}\mathrm{Si}$ and $^{23}\mathrm{Na}$ nuclear magnetic resonance (NMR) measurements of ${\mathrm{NaTiSi}}_{2}{\mathrm{O}}_{6}$. The use of magic angle spinning (MAS) techniques unambiguously shows that only one dynamically averaged silicon site can be seen at $T$ $>\phantom{\rule{4pt}{0ex}}{T}_{c}$. At cooling, the $^{29}\mathrm{Si}$ MAS NMR spectrum shows interesting changes. Immediately below ${T}_{c}$, the spectrum gets very broad. Cooling further, it shows two broad lines of unequal intensities which become narrower as the temperature decreases. Below 70 K, two narrow lines have chemical shifts that are typical for diamagnetic silicates. The hyperfine couplings for the two sites are $^{29}\mathrm{H}$ ${}_{\text{hf}}=7.4$ kOe/${\ensuremath{\mu}}_{B}$ and 4.9 kOe/${\ensuremath{\mu}}_{B}$. In the paramagnetic state at high temperature, the spin-lattice relaxation of $^{29}\mathrm{Si}$ was found to be weakly temperature dependent. Below ${T}_{c}$ the Arrhenius-type temperature dependence of the relaxation rate indicates an energy gap $\mathrm{\ensuremath{\Delta}}$/${\mathrm{k}}_{B}=1000(50)$ K. In the temperature region from 120 to 300 K, the relaxation rate was strongly frequency dependent. At room temperature, we found a power law dependence ${T}_{1}^{\ensuremath{-}1}\phantom{\rule{3.33333pt}{0ex}}\ensuremath{\propto}\phantom{\rule{3.33333pt}{0ex}}{\ensuremath{\omega}}_{L}^{\ensuremath{-}0.65(5)}$. For 70 K $<$ $T$ $<$ 120 K, the relaxation appeared to be nonexponential, which we assigned to a relaxation due to fixed paramagnetic centers. Simulation of the magnetization recovery curve showed activation type temperature dependence of the concentration of these centers. The NMR spectrum of $^{23}\mathrm{Na}$ shows the line with typical shape for the central transition of a quadrupolar nucleus. A small frequency shift of $^{23}\mathrm{Na}$ resonance corresponds to a very small hyperfine coupling $^{23}\mathrm{H}$ ${}_{\text{hf}}=0.32$ kOe/${\ensuremath{\mu}}_{B}$. In addition, at $T$ $>\phantom{\rule{4pt}{0ex}}{T}_{c}$ the $^{23}\mathrm{Na}$ spectrum shows another Lorentzian shaped resonance which we attribute to the Na sites where the quadrupolar coupling is partly averaged by ionic motion.

Single CrSi center in beta-SiO2 as a qubit application

A neutral CrSi center which consists of substituted chromium in the silicon site in beta-SiO2 was investigated by first-principles calculations. According to the spin-polarized electronic structures calculations, we found that the neutral CrSi center possesses a triplet ground state and the spin-conserved excited state was similar to NV−1 center in diamond. Moreover, combined with the first-principles calculations and perturbation theory, the spin zero-field splitting parameters of CrSi centers under different compression strains were calculated. The zero-field splitting parameters of the neutral CrSi center change significantly due to different strains. Based on all theoretical calculations and analysis, neutral CrSi centers are promising candidates for quantum strain sensor applications.

F+ center exchange mechanism and magnetocrystalline anisotropy in Ni-doped 3C-SiC

• F + center exchange mechanism has been invoked in order to explain the long range magnetic order in the system. • The Curie temperature is found to be above 350 K for all the doped samples obtained from the modified Bloch’s T 3/2 law. • The dynamic nature of the BMPs sizes have been studied extensively using Hc vs T data. • The spontaneous spin polarization has been induced in the system due to strong hybridization between (C) 2p and (Ni) 3d orbital. • The decrease in magneto crystalline anisotropy constant value with increase in temperature essentially indicates the weakening of the magnetic interaction in the system. • The incomplete quenching of orbital angular momentum and partial removal of orbital degeneracy resulted in reduction of line width and enhancement of integrated intensity as the temperature rises. Towards the development of a magnetic semiconductor suitable for spintronic device applications in extreme environments, we explored the possibility of inducing magnetic interaction in SiC by doping Nickel. The X-ray diffraction and Raman Spectroscopy studies confirm the incorporation of Ni into the host lattice. The magnetic measurements and electron spin resonance studies indicate the presence of room temperature ferromagnetic interaction in the system. The Curie temperature of 1, 3, and 5% Ni-doped samples have been found to be 420 K, 520 K, and 540 K respectively. Electron spin resonance study reveals that the valence state of Ni is 2 + , which implies the creation of vacancies at both Silicon (V Si ) and Carbon (V C ) sites as they are tetravalent. The change in magnetization of the system with an increase in dopant concentration is consistent with the variation in the number of vacancies and free holes. The analysis of magnetization data using the Law of approach to saturation shows that the anisotropic constant decreases with an increase in temperature. The long-range magnetic interaction in the system is explained using the F + center exchange mechanism.