Photoelectrochemical properties of MgTiO3 and other titanates with the ilmenite structure

Haart, L.G.J. de; Vries, A.J. De; Blasse, G.

doi:10.1016/0025-5408(84)90042-4

Cited by 51 publications

(27 citation statements)

References 21 publications

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“…The Co 2+ ! Ti 4+ CT interaction appeared around 550 nm, and the spin-allowed crystal-field transition is clearly visible for Co 2+ at 620 nm [16]. According to the model of Blasse et al [17], the 3rd ionization potential of Ni 2+ ion is greater than that of Co 2+ ion.…”

Section: Optical Absorptionmentioning

confidence: 96%

Synthesis and characterization of ilmenite NiTiO3 and CoTiO3 prepared by a modified Pechini method

Lin

Chang

Yang

et al. 2006

Journal of Non-Crystalline Solids

190

104

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Section: Optical Absorptionmentioning

confidence: 96%

Synthesis and characterization of ilmenite NiTiO3 and CoTiO3 prepared by a modified Pechini method

Lin

Chang

Yang

et al. 2006

Journal of Non-Crystalline Solids

190

104

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“…In the work by de Haart et al 43 the optical absorption edge and the onset wavelength for photocurrents is at 335 nm (3.7 eV) and the host absorption maximum is near 280 nm (4.4 eV) …”

Section: The Titanatesmentioning

confidence: 99%

Vacuum Referred Binding Energies of the Lanthanides in Transition Metal Oxide Compounds

Dorenbos

Rogers

2014

ECS J. Solid State Sci. Technol.

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The electronic level schemes for divalent and trivalent lanthanide ions in rare earth (La, Gd, Y, Lu, Sc) vanadate, niobate, tantalate, and in alkaline earth (Ba, Sr, Ca, Mg) titanate, molybdate, and tungstate compounds are presented. Use is made of data from luminescence excitation and absorption spectra of lanthanide (mostly Eu 3+ , Pr 3+ , and Tb 3+ ) impurities in those compounds. By means of the chemical shift model, binding energies, relative to the vacuum energy, of electrons in the impurity levels and the host bands are obtained. It reveals clear trends in conduction band and valence band energy with changing size of the rare earth or the alkaline earth ion. The bottom of the conduction band is dominated by 3d, 4d, or 5d orbitals, and it is found that the binding energy at the conduction band bottom tends to decrease with higher orbital number. The vanadates, titanates, molybdates, niobates, tungstates, and tantalates are widely used in many areas of applied physics and materials science. TiO 2 is famous for its photocatalytic activity used to produce hydrogen in electrochemical cells upon absorption of sunlight. Many other titanates and also vanadates are actively being studied for such applications.1 It is then crucial that the electron binding energy E V at the top of the valence band and E C at the bottom of the conduction band lie closely below and above the redox potentials for hydrogen and oxygen production. Lanthanides in transition metal (TM) based compounds can produce very bright luminescence. For bright luminescence to occur, the location of the emitting impurity level relative to E C is important. A location too close to E C will result in poor quantum efficiency or even a total absence of emission because of thermal or autoionization of the excited electron to the conduction band. Whether a lanthanide or a transition metal impurity can trap an electron from the conduction band or a hole from the valence band is also controlled by the impurity level locations in the band gap. 2That same location tells us the preferred impurity valence state.3 The above examples demonstrate that knowledge on the electronic structure, i.e., the absolute binding energy of the electrons in impurity states, host band states, or molecules, is crucial for our understanding of the performance of materials.There is an abundance of data on lanthanide spectroscopy covering many thousands of different compounds. Data that can provide information on the location of lanthanide impurity levels relative to the valence and conduction bands of the host compound. Once the location of the 4f n ground state energy of one particular lanthanide impurity is known, say Eu 2+ , then it can be predicted for all other divalent lanthanides. This good predictability is caused by the atomic like and well-shielded nature of the inner lanthanide 4f-orbitals.4 Host referred binding energy (HRBE) schemes as for GdVO 4 in Fig. 1 where all energies are referred to the top of the valence band, see the righthand energy scale, can be made routinel...

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“…3͒ in the energy range between Ϫ11 and Ϫ4 eV resembles that of the valence band in isostructural MgTiO 3 . 23 From optical-absorption measurements the band gap in MgTiO 3 was estimated to be 3.7 eV, 24 while the first energyloss structure in the resonant Ti L ␣,␤ spectra of FeTiO 3 ͑Fig. 3͒ is already observed at about 2.5 eV below recombination peak.…”

Section: Resonant Fluorescencementioning

confidence: 99%

Resonant inelastic soft-x-ray scattering from valence-band excitations in3d0compounds

et al. 1997

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Ti and Mn L ␣,␤ x-ray fluorescence spectra of FeTiO 3 and KMnO 4 were measured with monochromatic photon excitation on selected energies across the L 2,3 absorption edges. The resulting inelastic x-ray-scattering structures and their changes with varying excitation energies are interpreted within the framework of a localized, many-body approach based on the Anderson impurity model, where the radiative process is characterized by transitions to low-energy interionic-charge-transfer excited states. Sweeping the excitation energy through the metal 2p threshold enhances the fluorescence transitions to the antibonding states pushed out of the band of continuous states due to strong metal 3d -ligand 2p hybridization and matching the low-photon-energy satellites in the spectra. Based on the energy position of these charge-transfer satellites with respect to the recombination peak the effective metal 3d -ligand 2p hybridization strength in the ground state of the system can be estimated directly from the experiment. ͓S0163-1829͑97͒04508-6͔

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Photoelectrochemical properties of MgTiO3 and other titanates with the ilmenite structure

Cited by 51 publications

References 21 publications

Synthesis and characterization of ilmenite NiTiO3 and CoTiO3 prepared by a modified Pechini method

Synthesis and characterization of ilmenite NiTiO3 and CoTiO3 prepared by a modified Pechini method

Vacuum Referred Binding Energies of the Lanthanides in Transition Metal Oxide Compounds

Resonant inelastic soft-x-ray scattering from valence-band excitations in3d0compounds

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