Anatase to rutile phase transformation of iron-doped titanium dioxide nanoparticles: The role of iron content

Loan, Trinh Thi; Huong, Vu Hoang; Huyen, Nguyen Thi; Quyet, Lai Van; Bang, Ngac An; Long, Nguyen Ngoc

doi:10.1016/j.optmat.2020.110651

Cited by 24 publications

(15 citation statements)

References 38 publications

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“…The results were compared with pure anatase and rutile TiO 2 . For anatase, E g , B 1g , and A 1g peaks are ascribed to the symmetric stretching, symmetric bending, and asymmetric bending vibrations of O–Ti–O bands . For rutile, E g , B 1g , and A 1g peaks are ascribed to the asymmetric bending in the (001) plane, asymmetric bending in (001), (110), and (−110) planes, and symmetric stretching of the (110) plane of O–Ti–O bands, respectively .…”

Section: Results and Discussionmentioning

confidence: 99%

“…The Ti 3s peak at 63.24 eV is deconvoluted in between the Ir 4f peaks. The presence of the Ti 3s peak may indicate the formation of oxygen vacancies and defects (like Ti interstitials) in the TiO 2 crystal lattice. , Ir 4d 5/2 and Ir 4d 3/2 peaks are observed at 297.41 and 312.88 eV, respectively. Ir 4d peak values of 2% Ir-Ti400 are comparable to that of IrO 2 . , The changes in the peak intensity of O 1s peaks with respect to the mol % of Ir doping indicates the introduction of O 2 vacancies.…”

Section: Results and Discussionmentioning

confidence: 99%

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New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO₂

et al. 2021

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The impact of iridium (Ir) doping on the oxygen vacancies, relative stability, crystallite size, surface area, and anatase-to-rutile transition of TiO 2 was comprehensively investigated in this study. Ir-doped TiO 2 (Ir-TiO 2 ) was synthesized through a sol−gel technique, and the samples were annealed in the temperature range of 400−700 °C. Density functional theory calculations showed that the energy cost of an oxygen vacancy formation for Ir-TiO 2 was lower, as compared to that of the pristine TiO 2 , with the formation of Ir 3+ states in the band gap. Ir could provide more rutile nucleation sites and accelerate the rutile formation through the crystal strain relaxation. The entropy of mixing was reduced by the incorporation of Ir, which could induce the rutile formation with an increase in Gibbs free energy at temperatures below the normal phase transition temperature for pure TiO 2 . The rutile formation of Ir-TiO 2 could take place at a low annealing temperature (400 °C) compared to pristine TiO 2 (600 °C), indicating that the activation energy for phase transition could be decreased by incorporating Ir. XPS revealed the spin−orbit coupling of Ir 4f peaks, Ir 4f 7/2 (61.96 eV) and Ir 4f 5/2 (64.77 eV), due to the presence of Ir 3+ . Raman studies indicated the formation of charge-compensating oxygen vacancies and the presence of d states by Ir doping. It is concluded that the defects originated because the incorporation of Ir could facilitate rutile nucleation sites and thereby accelerate the phase transition through strain relaxation.

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Section: Results and Discussionmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO₂

et al. 2021

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“…The E g mode is associated with symmetric stretching, and B 1g belongs to symmetric bending vibrations of O-Ti-O group. When the temperature of deposition is increased for the S2 samples, a new signal at 437 cm −1 emerges, which can be attributed to asymmetric stretching of O-Ti-O bonding of rutile (110) plane [ 5 , 6 , 9 , 25 ].…”

Section: Resultsmentioning

confidence: 99%

“…Titanium oxide is a widely used functional material with many applications (from bulk materials as a pigment, ceramics technology and the catalysis of nanocrystalline powder to thin layered technology). In recent years, nanocrystalline titanium oxide was developed for solar energy [ 1 , 2 , 3 ], used in biomedical and photocatalytic applications [ 4 , 5 , 6 , 7 , 8 , 9 ], and used as an optical [ 10 ], self-cleaning, hydrophobic [ 1 , 11 , 12 , 13 ] and decorative coating [ 14 , 15 , 16 , 17 ]. Miszczak and Pietrzyk [ 11 ] found that the transformation from anatase to the rutile phase within thin film coatings occurs in a higher temperature regime than in the case of bulk TiO 2 .…”

Section: Introductionmentioning

confidence: 99%

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The Influence of Annealing on the Optical Properties and Microstructure Recrystallization of the TiO2 Layers Produced by Means of the E-BEAM Technique

et al. 2021

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Titanium dioxide films, about 200 nm in thickness, were deposited using the e-BEAM technique at room temperature and at 227 °C (500K) and then annealed in UHV conditions (as well as in the presence of oxygen (at 850 °C). The fabricated dielectric films were examined using X-ray powder diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, scanning electron microscopy, transmission electron microscopy, and spectroscopic ellipsometry. The applied experimental techniques allowed us to characterize the phase composition and the phase transformation of the fabricated TiO2 coatings. The films produced at room temperature are amorphous but after annealing consist of anatase crystallites. The layers fabricated at 227 °C contain both anatase and rutile phases. In this case the anatase crystallites are accumulated near the substrate interface whilst the rutile crystallites were formed closer to the surface of the TiO2 film. It should be emphasized that these two phases of TiO2 are distinctly separated from each other.

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Effects of manganese concentration and temperature on the ferromagnetism of manganese‐doped gallium arsenide semiconductor

Abera,

Mekuye

2023

Nano Select

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The main objective of the review was to investigate the ferromagnetism of diluted magnetic semiconductors made of Mn‐doped GaAs. Manganese‐doped gallium arsenide has recently become an important field of research because of its potential applications in the fields of spintronics and magnetic devices. The magnetic moment caused by adding manganese to the GaAs crystal structure causes a low‐temperature ferromagnetic behavior. The main factor that affects the ferromagnetic properties of Mn‐doped gallium arsenic is manganese concentration. Understanding the relationship between Mn concentration and magnetic properties is important for material optimization in specific applications. It was found that Mn‐doped GaAs exhibit paramagnetic behavior below a specific critical concentration. However, the substance is transformed into a ferromagnetic state over the maximum concentration. The Curie temperature is an important additional factor influencing the ferromagnetic properties of Mn‐doped GaAs. The temperature at which a material ceases to exhibit ferromagnetic behavior is known as the Curie temperature. The Curie temperature of a material depends on its Mn concentration, thin film thickness, and degree of disturbance. A reduction in magnetic resistance increases the concentration of Mn‐treated gallium arsenic and increases its rate as it reaches its maximum value. High Curie temperatures are the result of stronger magnetic interactions resulting from higher manganese concentrations. The specific heat capacity of Mn‐doped gallium arsenide is influenced by its magnetic and structural contribution.

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Anatase to rutile phase transformation of iron-doped titanium dioxide nanoparticles: The role of iron content

Cited by 24 publications

References 38 publications

New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO₂

New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO₂

The Influence of Annealing on the Optical Properties and Microstructure Recrystallization of the TiO2 Layers Produced by Means of the E-BEAM Technique

Effects of manganese concentration and temperature on the ferromagnetism of manganese‐doped gallium arsenide semiconductor

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Anatase to rutile phase transformation of iron-doped titanium dioxide nanoparticles: The role of iron content

Cited by 24 publications

References 38 publications

New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO2

New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO2

The Influence of Annealing on the Optical Properties and Microstructure Recrystallization of the TiO2 Layers Produced by Means of the E-BEAM Technique

Effects of manganese concentration and temperature on the ferromagnetism of manganese‐doped gallium arsenide semiconductor

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New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO₂

New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO₂