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

doi:10.1186/1556-276X-8-533

Home
/
Papers
/
Influence of transition metal doping on the structural, optical, and magnetic properties of TiO2 films deposited on Si substrates by a sol-gel process.

Journal Article•DOI•

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

Jianjun Tian¹, Jianjun Tian², Huiping Gao¹, Hui Kong², Pingxiong Yang², Weifeng Zhang¹, Junhao Chu² - Show less +3 more•Institutions (2)

Henan University¹, East China Normal University²

19 Dec 2013-Nanoscale Research Letters (Springer)-Vol. 8, Iss: 1, pp 533-533

TL;DR: It is found that the magnetizations of the TM-doped TiO2 films decrease with increasing dopant content, which is related to electric disorder due to the ART.

read less

Abstract: 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.

...read moreread less

Content maybe subject to copyright Report

Citations

PDF

Open Access

More filters

Journal Article•DOI•

Fabrication of Fe-doped TiO2 nanoparticles and investigation of photocatalytic decolorization of reactive red 198 under visible light irradiation

[...]

Halimeh Moradi¹, Akbar Eshaghi¹, Seyed Rahman Hosseini¹, Kamal Ghani¹•Institutions (1)

Malek-Ashtar University of Technology¹

01 Sep 2016-Ultrasonics Sonochemistry

TL;DR: Among the samples, Fe-1wt% doped TiO2 nanoparticles showed the highest photocatalytic decolorization of RR198 under visible light irradiation.

...read moreread less

136 citations

Journal Article•DOI•

Magnetic and ferroelectric properties of Ni doped BaTiO3

[...]

S. K. Das¹, R. N. Mishra¹, B. K. Roul•Institutions (1)

Ravenshaw University¹

01 Aug 2014-Solid State Communications

TL;DR: In this article, structural, magnetic and ferroelectric properties of Ni doped barium titanate were investigated using solid state sintering technique and it was revealed from structural studies that the phase transformation from tetragonal to hexagonal phase is strongly influenced by Ni doping concentration.

...read moreread less

92 citations

Journal Article•DOI•

Room-temperature ferromagnetism in Ni-doped TiO2 diluted magnetic semiconductor thin films

[...]

Bushra Parveen¹, Mahmood-ul-Hassan¹, Zeeshan Khalid¹, Saira Riaz¹, Shahzad Naseem¹ - Show less +1 more•Institutions (1)

University of the Punjab¹

01 Apr 2017-Journal of Applied Research and Technology

TL;DR: In this paper, undoped and Ni-doped TiO 2 ( x Ni ǫ = 0.00, 0.50, 1.00 and 2.50 ) thin films fabricated on glass substrates by using a combination of solid-state reaction and dip coating techniques.

...read moreread less

67 citations

Journal Article•DOI•

Enhanced Rate Capability and Cycle Performance of Titanium-Substituted P2-Type Na0.67Fe0.5Mn0.5O2 as a Cathode for Sodium-Ion Batteries.

[...]

Joon-ki Park¹, Geun-gyung Park¹, Hunho H. Kwak², Seung-Tae Hong², Jae-Won Lee¹ - Show less +1 more•Institutions (2)

Dankook University¹, Daegu Gyeongbuk Institute of Science and Technology²

11 Jan 2018

TL;DR: The enhanced rate capability and cycling stability were attributed to the enlargement of the NaO2 slab in the crystal structure because of Ti doping, which promoted Na-ion diffusion and prevented the phase transition from the P2 to the OP4/″Z″ structure.

...read moreread less

Abstract: In this study, we developed a doping technology capable of improving the electrochemical performance, including the rate capability and cycling stability, of P2-type Na0.67Fe0.5Mn0.5O2 as a cathode material for sodium-ion batteries. Our approach involved using titanium as a doping element to partly substitute either Fe or Mn in Na0.67Fe0.5Mn0.5O2. The Ti-substituted Na0.67Fe0.5Mn0.5O2 shows superior electrochemical properties compared to the pristine sample. We investigated the changes in the crystal structure, surface chemistry, and particle morphology caused by Ti doping and correlated these changes to the improved performance. The enhanced rate capability and cycling stability were attributed to the enlargement of the NaO2 slab in the crystal structure because of Ti doping. This promoted Na-ion diffusion and prevented the phase transition from the P2 to the OP4/″Z″ structure.

...read moreread less

62 citations

Journal Article•DOI•

Enhanced hydrogen evolution from water splitting using Fe-Ni codoped and Ag deposited anatase TiO2 synthesized by solvothermal method

[...]

Tao Sun¹, Tao Sun², Enzhou Liu¹, Xuhua Liang¹, Xiaoyun Hu¹, Jun Fan¹ - Show less +2 more•Institutions (2)

Northwest University (China)¹, Nanjing University²

30 Aug 2015-Applied Surface Science

TL;DR: In this paper, the Fe-Ni co-doped and Ag deposited anatase TiO2 (Fe-Ni/Ag/TiO2) nanocomposites were successfully prepared by a simple one-pot solvothermal approach.

...read moreread less

55 citations

1
2
3
4
…
5
6
7
8
9
10
11

Collapse

References

PDF

Open Access

More filters

Journal Article•DOI•

Oxygen vacancy induced structural phase transformation in TiO2 nanoparticles

[...]

Chandana Rath¹, Pankaj Kumar Mohanty¹, Avinash C. Pandey², N. C. Mishra³•Institutions (3)

Banaras Hindu University¹, Allahabad University², Utkal University³

21 Oct 2009-Journal of Physics D

TL;DR: In this paper, the anatase to rutile phase transformation (ART) occurs at 650°C in the case of pH 6.5 while 850°C is the ART temperature for the lower pH sample.

...read moreread less

Abstract: Nanosize TiO2 powders prepared by the sol–gel technique at pH of precipitation 4.5 and 6.5 show the anatase phase after calcining at 500 °C. Anatase to rutile phase transformation (ART), however, occurs at 650 °C in the case of pH 6.5 while 850 °C is found to be the ART temperature for the lower pH sample. pH of precipitation dependent ART temperature has not been reported so far to the best of our knowledge. It is known that the smaller the particle size, the lower the ART temperature, and vice versa. The observation of higher crystallite size and lower ART temperature in the case of the higher pH sample contradicts the reported result. We realized from x-ray photoelectron spectroscopic studies that oxygen vacancy concentration drives the ART temperature to lower values in the higher pH sample compared with the sample synthesized at lower pH; even the particle size is found to be higher in the former one.

...read moreread less

201 citations

"Influence of transition metal dopin..." refers background in this paper

...The OI peak is due to the oxygen atoms of TiO2 [24,28], and the OII peak is attributed to the oxygen vacancies [24,26,29]....
[...]
...The influence of the Co and Ni dopants on the ART of the TiO2 films is conspicuous, but minimal for the Fe dopant....
[...]
...There are oxygen vacancies in our samples and the va- cancies promote the ART....
[...]
...With the same dopant content, Co doping catalyzing the ART is more obvious than those of Ni doping and Fe doping, which is attributed to the different strain energy induced by oxygen vacancies and the difference in valence and ionic radii of Co2+, Ni2+, and Fe3+....
[...]
...7 eV in the two peaks indicates a valence state of +4 for Ti in the TiO2and Ni-doped TiO2 samples [24,25]....
[...]

Journal Article•DOI•

Kinetics of the anatase–rutile transformation in TiO2 in the presence of Fe2O3

[...]

Fabiana C. Gennari, Daniel M. Pasquevich

01 Mar 1998-Journal of Materials Science

TL;DR: In this article, the anatase-rutile phase transition in TiO2 in the presence of Fe2O3 was investigated in air and argon atmospheres by means of X-ray diffraction and scanning electron microscopy.

...read moreread less

Abstract: The anatase–rutile phase transition in TiO2 in the presence of Fe2O3 was investigated in air and argon atmospheres by means of X-ray diffraction and scanning electron microscopy. Isothermal curves of rutile transformed from anatase as a function of time were obtained between 825 and 950 °C. The data were well fitted by various rate laws. In the presence of Fe3+, the anatase–rutile transition temperature is lower and the transformation rate in air is higher than the corresponding one in pure TiO2. The transformation in the presence of Fe3+ in an argon atmosphere is more rapid than in air. The enhancement effect of Fe3+ on the anatase–rutile transformation in both atmospheres is understood on the basis of the formation of oxygen vacancies.

...read moreread less

166 citations

"Influence of transition metal dopin..." refers result in this paper

...For Fe-doped TiO2 film, the anatase phase is still prominent, and the EOBG value is 3.54 ± 0.02 eV....
[...]
...Thus, the rutile content of Co- or Ni-doped TiO2 films is more than that of the Fe-doped TiO2 films....
[...]
...The M values of doped samples decrease with increasing metal element contents, which is similar to the Ni-doped TiO2 powders [21] and Fe-doped TiO2 films [52]....
[...]
...The same analysis also shows a valence state of +2 for Co in Co-doped TiO2 and a valence state of +3 for Fe in Fe-doped TiO2 (in Figure 3)....
[...]
...At the same dopant content, the rutile content of the Co-doped TiO2 films is the highest, and that of Fe-doped TiO2 films is the lowest....
[...]

Journal Article•DOI•

Band Lineup and Charge Carrier Separation in Mixed Rutile-Anatase Systems

[...]

Peter Deák¹, Bálint Aradi¹, Thomas Frauenheim¹•Institutions (1)

University of Bremen¹

04 Feb 2011-Journal of Physical Chemistry C

TL;DR: In this paper, the authors used the HSE06 functional for rutile and anatase crystals to reproduce the observed width of the valence and conduction bands, as well as the gap.

...read moreread less

Abstract: Calculations by the HSE06 functional for rutile and anatase crystals reproduce the observed width of the valence and conduction bands, as well as of the gap. From the band structures the branching point energies are obtained as reference for both phases, allowing us to deduce a generic band alignment scheme without a specific interface model. The results show that both bands of rutile lie higher than those of anatase, so in mixed systems the holes are accumulated in the former while the electrons in the latter. Consequences for photocatalytic and photoelectrochemical applications are discussed.

...read moreread less

154 citations

"Influence of transition metal dopin..." refers background in this paper

...In recent years, mixed crystal TiO2 containing anatase and rutile phases has been more attractive because the anatase-rutile-phase junction (ARJ, related to phase composition) in the mixed crystal TiO2 improves the spatial charge separation and enhances the photocatalytic activity [12-16]....
[...]

Journal Article•DOI•

The Growth Mechanism of Nickel Oxide Thin Films by Room-Temperature Chemical Bath Deposition

[...]

Seung-Yeol Han¹, Seung-Yeol Han², Doo-Hyoung Lee², Yu-Jen Chang², Si Ok Ryu¹, Si Ok Ryu², Tae Jin Lee¹, Chih-Hung Chang² - Show less +4 more•Institutions (2)

Yeungnam University¹, Oregon State University²

01 Jun 2006-Journal of The Electrochemical Society

TL;DR: In this paper, a growth mechanism based on the combination of particle sticking and molecule level heterogeneous growth was proposed for nickel oxide thin films, which was converted to nickel oxide (NiO) by thermal annealing according to thermogravimetric.

...read moreread less

Abstract: Chemical bath deposition (CBD) is an advantageous thin film deposition technique for depositing compound semiconductors at low temperature. In this paper, nickel oxide thin films were prepared by CBD from an aqueous solution composed of nickel sulfate, potassium persulfate, and ammonia at room temperature. Thin film growth mechanisms were studied by using quartz crystal microbalance, UV-vis absorption, and photon correlation spectroscopy. The data indicate that film growth is strongly dependent upon mixing conditions and competes with homogeneous particle formation. No film formation was observed without the addition of persulfate. A growth mechanism based on the combination of particle sticking and molecule level heterogeneous growth is proposed. The as-deposited film contained α-Ni(OH) 2 and 4Ni(OH) 2 ·NiOOH·xH 2 O and was converted to nickel oxide (NiO) by thermal annealing according to thermogravimetric. X-ray diffraction and X-ray photoelectron spectroscopy measurements.

...read moreread less

127 citations

"Influence of transition metal dopin..." refers background in this paper

...1 eV) [25,26] and very near to that of Ni (855 eV) [21,25,27]....
[...]

Journal Article•DOI•

Modification of the phase transition temperatures in titania doped with various cations

[...]

R. Rodríguez-Talavera¹, Susana Vargas¹, R. Arroyo-Murillo¹, R. Montiel-Campos¹, Emmanuel Haro-Poniatowski¹ - Show less +1 more•Institutions (1)

Universidad Autónoma Metropolitana¹

01 Feb 1997-Journal of Materials Research

TL;DR: In this paper, the effect of the dopants on the thermal and structural properties of the materials is analyzed using x-ray diffraction, showing that the amorphous-anatase transition is independent, for almost all samples, of the type of dopant used; however, the anatase-to-rutile phase transition depends strongly on the kind of cation.

...read moreread less

Abstract: Titania matrices prepared by a sol-gel technique were doped with several cations (La, Zn, Al, K, Na, Ca, Ba, and Co). The effect of the dopants on the thermal and structural properties of the materials is analyzed. The dopant concentration was 2% mol with respect to titanium, and in all cases the same anion (nitrate) was used. The transition temperatures from amorphous to anatase and from anatase to rutile were measured using x-ray diffraction. The amorphous-anatase transition is independent, for almost all samples, of the type of dopant used; however, the anatase-to-rutile phase transition depends strongly on the kind of cation. This means that the temperature range where the anatase phase exists can be controlled by choosing the appropriate dopant. We have found a correlation between the anatase-rutile phase transition temperature and the radius of the cations and their electric charge.

...read moreread less

119 citations

"Influence of transition metal dopin..." refers background or result in this paper

...The influence of the Co and Ni dopants on the ART of the TiO2 films is conspicuous, but minimal for the Fe dopant....
[...]
...When the Ti ions are substituted by TM (Co, Ni, and Fe) ions, the difference in ionic radii between Ti and TM results in the lattice deformation of anatase TiO2, and the strain energy due to the lattice deformation facilitates the ART [33]....
[...]
...There are oxygen vacancies in our samples and the va- cancies promote the ART....
[...]
...With the same dopant content, Co doping catalyzing the ART is more obvious than those of Ni doping and Fe doping, which is attributed to the different strain energy induced by oxygen vacancies and the difference in valence and ionic radii of Co2+, Ni2+, and Fe3+....
[...]
...According to XRD analysis, the ART easily occurs in anatase TiO2 lattice with oxygen vacancies....
[...]