Ferromagnetic Properties of Ni-Doped Rutile TiO2-delta

Ran, Young; Seung-Li, Seung-Li; Han, Jeongsoo; Joo, Kwang; Chul, Sung

doi:10.3938/jkps.50.638

Cited by 16 publications

(8 citation statements)

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“…The ferromagnetic hysteresis curves are clearly found for all samples, which indicate that the undoped and doped TiO 2 films exhibit ferromagnetic behavior. The results are similar to those of the literature [21,48-51]. In addition, the M values of x = 0.01 Fe-, Ni-, and Co-doped TiO 2 films at 10 4 Oe were the largest and about 419.7, 386.5, and 445.6 emu/cm 3 , respectively.…”

Section: Resultssupporting

confidence: 90%

“…In the center, the trapped electron occupying an orbital effectively overlaps the d shells of the surrounding magnetic ions. Therefore, a possible origin of ferromagnetism is an F -center-bound magnetic polaron, which is formed by an electron trapped in an oxygen vacancy and its neighboring magnetic impurity ions [8,51]. In other words, the room-temperature ferromagnetism of TM-doped TiO 2 films was induced mainly by the magnetic polarons formed by the localized electrons surrounded by magnetic impurities.…”

Section: Resultsmentioning

confidence: 99%

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Influence of transition metal doping on the structural, optical, and magnetic properties of TiO2 films deposited on Si substrates by a sol–gel process

et al. 2013

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Transition metal (TM)-doped TiO2 films (TM = Co, Ni, and Fe) were deposited on Si(100) substrates by a sol–gel method. With the same dopant content, Co dopants catalyze the anatase-to-rutile transformation (ART) more obviously than Ni and Fe doping. This is attributed to the different strain energy induced by the different dopants. The optical properties of TM-doped TiO2 films were studied with spectroscopic ellipsometry data. With increasing dopant content, the optical band gap (EOBG) shifts to lower energy. With the same dopant content, the EOBG of Co-doped TiO2 film is the smallest and that of Fe-doped TiO2 film is the largest. The results are related to electric disorder due to the ART. Ferromagnetic behaviors were clearly observed for TM-doped TiO2 films except the undoped TiO2 film which is weakly magnetic. Additionally, it is found that the magnetizations of the TM-doped TiO2 films decrease with increasing dopant content.

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Section: Resultssupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

Influence of transition metal doping on the structural, optical, and magnetic properties of TiO2 films deposited on Si substrates by a sol–gel process

et al. 2013

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“…Many experimental studies reported on the synthesis and the characterization of 3d TM doped rutile TiO2 materials. 26,36,39,40,[43][44][45]47,51,[83][84][85][86][87][88][89][90][91] Figure 6b sums up the domain limits of cationic species in this specific host material as proposed by Mizushima et al [43][44][45]47 based on experimental (e.g., photocurrent) and theoretical (semi-empirical model supported by photoconductivity and photo-ESR measurements) considerations. Namely, experimentally observed ionic species in TiO2rutile, i.e., V 5+ , V 4+ and V 3+ 26,44,51 , Mn 4+ , Mn 3+ and Mn 2+ 47,51,83-85 , Fe 4+ and Fe 3+ 39,43,47,51,86,88,91 , Cu 2+ and possibly Cu + 89,90 , and Ni 3+ and Ni 2+ 36,40,51 , possibly stabilized for different material's shape (nanorods, nanopowders, thin films) are predicted from our simulations.…”

Section: Transition Metal Impuritiesmentioning

confidence: 99%

“…These intentionally introduced point defects are well-known to create local structural distortions and in-gap electronic states, [16][17][18][19][20] which may significantly modify the electronic, magnetic and/or optical properties of host materials. In the case of the TiO2 compound, the introduction of transition metal (TM) dopants has been reported to enhance photocatalytic, [21][22][23][24][25][26][27][28][29] electrocatalytic 30,31 or ferromagnetic [32][33][34][35][36][37][38][39][40][41] properties, but also to alter the irreversible anatase-torutile phase transition. 42 It remains evident that properties strongly depend on the electronic configuration of impurities, which is usually discussed through their oxidation state.…”

Section: Introductionmentioning

confidence: 99%

Ab Initio Prediction of the Redox Potentials of 3d Transition Metals Embedded in a Semiconducting Host Lattice

2021

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Here, we report a theoretical investigation devoted to the ab initio determination of the redox potentials E(D n+ /D n+1 ) of a dopant D in a given host lattice. The knowledge of these potentials is of capital importance to anticipate its attainable oxidation states (versus the synthesis conditions).Hereafter the host lattice has been selected to be the well-known rutile TiO2 compound due to its interest for many applications, the simplicity of its crystal structure and the large number of already collected data. Dopants are 3d transition metals (i.e., V, Mn, Fe, Ni and Cu) substituting titanium atoms. First-principles methods combined to the SCAN functional were used to determine the electronic properties of doped materials considering the supercell approach. The stability of point defects (intrinsic and extrinsic) at different charge states are discussed based on the estimation of their defect formation enthalpies, and the associated charge transition levels are calculated and positioned in the gap of the un-doped material.

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“…As in the spectrum of the TO-Ni-02 material, the N1′ component corresponded to Ni 2+ ions embedded in the TiO 2 (B) lattice at the Ti 4+ positions. The N3 component, the g -factor value of which significantly exceeded that of isolated Ni 2+ ions, possibly belonged to the ferromagnetically ordered structures of nickel, perhaps magnetic nickel clusters, formed from the excess dopant on its surface and/or in the pores [ 53 ]. In addition, the carrier of ferromagnetism in TO-Ni-05 can be an F -center-bound magnetic polaron [ 54 , 55 ].…”

Section: Resultsmentioning

confidence: 99%

Enhancing Lithium and Sodium Storage Properties of TiO2(B) Nanobelts by Doping with Nickel and Zinc

et al. 2021

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Nickel- and zinc-doped TiO2(B) nanobelts were synthesized using a hydrothermal technique. It was found that the incorporation of 5 at.% Ni into bronze TiO2 expanded the unit cell by 4%. Furthermore, Ni dopant induced the 3d energy levels within TiO2(B) band structure and oxygen defects, narrowing the band gap from 3.28 eV (undoped) to 2.70 eV. Oppositely, Zn entered restrictedly into TiO2(B), but nonetheless, improves its electronic properties (Eg is narrowed to 3.21 eV). The conductivity of nickel- (2.24 × 10−8 S·cm−1) and zinc-containing (3.29 × 10−9 S·cm−1) TiO2(B) exceeds that of unmodified TiO2(B) (1.05 × 10−10 S·cm−1). When tested for electrochemical storage, nickel-doped mesoporous TiO2(B) nanobelts exhibited improved electrochemical performance. For lithium batteries, a reversible capacity of 173 mAh·g−1 was reached after 100 cycles at the current load of 50 mA·g−1, whereas, for unmodified and Zn-doped samples, around 140 and 151 mAh·g−1 was obtained. Moreover, Ni doping enhanced the rate capability of TiO2(B) nanobelts (104 mAh·g−1 at a current density of 1.8 A·g−1). In terms of sodium storage, nickel-doped TiO2(B) nanobelts exhibited improved cycling with a stabilized reversible capacity of 97 mAh·g−1 over 50 cycles at the current load of 35 mA·g−1.

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Ferromagnetic Properties of Ni-Doped Rutile TiO2-delta

Cited by 16 publications

References 0 publications

Influence of transition metal doping on the structural, optical, and magnetic properties of TiO2 films deposited on Si substrates by a sol–gel process

Influence of transition metal doping on the structural, optical, and magnetic properties of TiO2 films deposited on Si substrates by a sol–gel process

Ab Initio Prediction of the Redox Potentials of 3d Transition Metals Embedded in a Semiconducting Host Lattice

Enhancing Lithium and Sodium Storage Properties of TiO2(B) Nanobelts by Doping with Nickel and Zinc

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