Extra EPR Spectra of Iron-Doped Rutile

Andersson, Per‐Olof; Kollberg, E.; Jelenski, A.

doi:10.1103/physrevb.8.4956

Cited by 33 publications

(8 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the Fe case the computed position of ͑0.54a , 0.10b ,0c͒ is in excellent agreement with that deduced from EPR measurements ͑0.56a , 0.11b ,0c͒. 13 The preference of the H ions for bonding at the shared edge of Ti and Al octahedra is largely electrostatic in origin. The Al +3 ion is more electronegative than the Ti +4 ions and thus its nearest neighboring Ti ions (which are along the c directions) are partly oxidized having charges of 1.41͉e͉ compared to 1.36-1.37͉e͉ on other Ti ions.…”

Section: A Position Of a Protonsupporting

confidence: 83%

“…In Al-doped rutile the Raman data is significantly different and does not exclude this symmetry element and so the BOE model may pertain in this case 11 while EPR measurements of Fe-doped rutile support the CC model. 13 Neutron diffraction data from a sample of a natural mantle rutile place H ions near the BOE position in a bent O-H-O configuration.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

First-principles study of H intercalation in rutileTiO2

2004

View full text Add to dashboard Cite

The geometry of hydrogen intercalation sites in rutile TiO 2 has been studied using first principles calculations. A new intercalation site is predicted which is consistent with all current experimental data. The apparent contradiction between spectroscopic, diffraction and magnetic resonance data are resolved by taking into account the strong local distortions of the structure induced by localization of donated charge. In particular the predicted OH vibrational frequency is in excellent agreement with that measured. A similar local geometry is predicted in the presence of 3+ counter ions but with a preferential site occupancy which is consistent with the local symmetry implied by spectroscopic measurements of aluminium substituted titania. The local distortions of the structure are shown to result in preferential ordering of the hydrogen ions in layers over a wide range of intercalation concentrations and the consequences of this ordering for electrochemical insertion of hydrogen are discussed.

show abstract

Section: A Position Of a Protonsupporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

First-principles study of H intercalation in rutileTiO2

2004

View full text Add to dashboard Cite

show abstract

“…If the W site is shifted from the (t, 0, 0) position toward one of the nearby 0 2 -ions as suggested by the recent work of Anderson et at. 13 Do 1 is reduced by -15%. The agreement of the measured value of Do II with Eqo (4) is surprisingly good, possibly because the time required for such a jump is very short, thus minimizing lattice relaxation effects.…”

Section: Resultsmentioning

confidence: 94%

Diffusion of H and D in TiO2: Suppression of internal fields by isotope exchange

Johnson

Paek

DeFord

1975

Journal of Applied Physics

156

View full text Add to dashboard Cite

Measurements of Hand D diffusion in Ti0 2 • using the isotope exchange technique described in the preceding paper. are reported. Use of this technique resulted in diffusion which was accurately described by Fick's law with a constant diffusion coefficient, as predicted theoretically. in sharp contrast to single ion diffusion, where dramatic departures from classical diffusion theory were observed. The measured diffusion coefficients for H were 1.8X 10-3 exp( -O.5geV/kT) and 3.8X 10-1 exp( -1.28eV/kT) cm 2 /sec for diffusion II and 1 to the c axis, respectively. Ionic conductivity measurements are reported. which agree well with the bulk diffusion measurements. and permitted us to extend the temperature range of the measurements for c -axis diffusion from 125 to 750"C, corresponding to a range of more than four orders of magnitude in D. The measured diffusion parameters were found to be essentially independent of sample purity. although it was observed that significant concentrations of lattice defects sharply inhibited H diffusion.

show abstract

“…Regions of low electron density exist between the chains, forming the so-called "c channel". Earlier studies have shown that interstitial H resides in the c channel, leading to the formation of an OH bond (with a length of 0.109 nm) perpendicular to the ĉ axis 17 . The open channels cause anisotropy in the diffusion process, and may allow fast diffusion of smaller ions parallel to the tetragonal axis.…”

Section: Introductionmentioning

confidence: 99%

Electronic structure of Mu-complex donor state in rutileTiO2

et al. 2015

View full text Add to dashboard Cite

The hyperfine structure of the interstitial muonium (Mu) in rutile (TiO2, weakly n-type) has been identified by means of a muon spin rotation technique. The angle-resolved hyperfine parameters exhibit a tetragonal anisotropy within the ab plane and axial anisotropy with respect to the 001 (ĉ) axis. This strongly suggests that the Mu is bound to O (forming an OH bond) at an offcenter site within a channel along theĉ axis, while the unpaired Mu electron is localized around the neighboring Ti site. The hyperfine parameters are quantitatively explained by a model that considers spin polarization of the unpaired electron at both the Ti and O sites, providing evidence for the formation of Mu as a Ti-O-Mu complex paramagnetic state. The disappearance of the Mu signal above ∼10 K suggests that the energy necessary for the promotion of the unpaired electron to the conduction band by thermal activation is of the order of 10 1 meV. These observations suggest that, while the electronic structure of Mu (and hence H) differs considerably from that of the conventional shallow level donor described by the effective mass model, Mu supplies a loosely bound electron, and thus, serves as a donor in rutile.

show abstract

Extra EPR Spectra of Iron-Doped Rutile

Cited by 33 publications

References 11 publications

First-principles study of H intercalation in rutileTiO2

First-principles study of H intercalation in rutileTiO2

Diffusion of H and D in TiO2: Suppression of internal fields by isotope exchange

Electronic structure of Mu-complex donor state in rutileTiO2

Contact Info

Product

Resources

About