Hydrogen impurity in yttria:<i>Ab initio</i>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>μ</mml:mi></mml:math>SR perspectives

Silva, E. Lora da; Marinopoulos, A. G.; Vilão, R. C.; Vieira, R. B. L.; Alberto, H. V.; Duarte, J. Piroto; Gil, J. M.

doi:10.1103/physrevb.85.165211

Cited by 35 publications

(59 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Muonium spectroscopy has the particular advantage of corresponding to the high-dilution limit for the muonium impurity, which can thus quite generally be considered isolated and is affected only indirectly by other defects and impurities (including hydrogen impurities) through the overall Fermi energy. Extensive studies have thus been carried out to characterize the muonium centers formed in different semiconductors and oxides [12,13,[19][20][21] and the respective results for the muonium configurations compare well with those obtained with protons, for the very few cases allowing comparison [9,[22][23][24][25].…”

Section: Introductionmentioning

confidence: 67%

“…The investigation of the role of hydrogen in semiconductors and oxides has assumed increasing and vital importance since the discovery that this impurity can be the source of n-type conductivity in II-VI semiconducting compounds [8,9]. This subject has seen * vieira.fis@gmail.com notable advances from the interplay of theoretical predictions from calculations based on density-functional theory (DFT) and muon-spin rotation (μSR) spectroscopy [10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Isolated hydrogen configurations in zirconia as seen by muon spin spectroscopy andab initiocalculations

et al. 2016

Self Cite

View full text Add to dashboard Cite

We present a systematic study of isolated hydrogen in diverse forms of ZrO 2 (zirconia), both undoped and stabilized in the cubic phase by additions of transition-metal oxides (Y 2 O 3 , Sc 2 O 3 , MgO, CaO). Hydrogen is modeled by using muonium as a pseudoisotope in muon-spin spectroscopy experiments. The muon study is also supplemented with first-principles calculations of the hydrogen states in scandia-stabilized zirconia by conventional density-functional theory (DFT) as well as a hybrid-functional approach which admixes a portion of exact exchange to the semilocal DFT exchange. The experimentally observable metastable states accessible by means of the muon implantation allowed us to probe two distinct hydrogen configurations predicted theoretically: an oxygen-bound configuration and a quasiatomic interstitial one with a large isotropic hyperfine constant. The neutral-oxygen-bound configuration is characterized by an electron spreading over the neighboring zirconium cations, forming a polaronic state with a vanishingly small hyperfine interaction at the muon. The atom-like interstitial muonium is observed also in all samples but with different fractions. The hyperfine interaction is isotropic in calcia-doped zirconia [A iso = 3.02(8) GHz], but slightly anisotropic in the nanograin yttria-doped zirconia [A iso = 2.1(1) GHz, D = 0.13(2) GHz] probably due to muons stopping close to the interface regions between the nanograins in the latter case.

show abstract

Section: Introductionmentioning

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Isolated hydrogen configurations in zirconia as seen by muon spin spectroscopy andab initiocalculations

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…Exchange-correlation effects were treated in the framework of the local density approximation (LDA), generalized gradient approximation (GGA) with PerdewBurke-Ernzerhof (PBE) parametrization, and GGA-PBEsol exchange correlation (for solids calculations) to obtain equilibrium structures [25][26][27][28]. The GGA-PBEsol exchange correlation was only used to obtain the elastic properties and electronic structures because it yielded the most accurate values in structural optimizations compared with experimental values.…”

Section: Calculation Methodsmentioning

confidence: 99%

Elastic and electronic properties of partially ordered and disordered Zr(C1−N ) solid solution compounds: A first principles calculation study

Kim

Kwon

Kim

et al. 2015

Journal of Alloys and Compounds

View full text Add to dashboard Cite

“…It is usually assumed that information obtained from μSR can be transferred with appropriate modifications to H. However, overlapping experiments to support this assumption are scarce. A particularly relevant case is the doping character of H in semiconductors and oxides [3][4][5][6], where practically all calculations refer to the electronic structure of H whereas most experimental information comes from μSR [7][8][9][10][11][12][13]. Overlapping data exist only for ZnO where proton-ENDOR (electron-nuclear double resonance) data [14] can be compared directly with μSR results [15][16][17][18].…”

mentioning

confidence: 99%

Muonium donor in rutileTiO2and comparison with hydrogen

et al. 2015

Self Cite

View full text Add to dashboard Cite

Muonium, a positive muon and an electron, is often used as an experimentally accessible substitute for hydrogen in materials research. In semiconductors and insulators, a large amount of information on the hydrogen behavior is deduced from this analogy; however, it is seldom demonstrated that this procedure is justified. We show here, via a comparison of the hyperfine interactions, that in TiO 2 muonium and hydrogen form the same configuration with the same basic electronic structure. A detailed description of the bonding characteristics of the muon to the Ti 3+ polaron is presented. The special role of muon motion within the so-called oxygen channel in the rutile structure, which occurs at a lower temperature than for hydrogen, is emphasized. Muonium (Mu) is a pseudoisotope of hydrogen in which the proton is replaced by a positive muon (μ + ), with a factor of 9 lighter mass. Muon spin spectroscopy (μSR) uses muons implanted with 100% spin polarization and offers a very sensitive method to study the properties of this isolated pseudohydrogen in solids [1,2]. It is usually assumed that information obtained from μSR can be transferred with appropriate modifications to H. However, overlapping experiments to support this assumption are scarce. A particularly relevant case is the doping character of H in semiconductors and oxides [3][4][5][6], where practically all calculations refer to the electronic structure of H whereas most experimental information comes from μSR [7][8][9][10][11][12][13]. Overlapping data exist only for ZnO where proton-ENDOR (electron-nuclear double resonance) data [14] can be compared directly with μSR results [15][16][17][18]. A number of properties (e.g., ionization energy) are indeed similar for the two species. However, the measured hyperfine interaction (hfi), scaled with the magnetic moments, differs by almost a factor of 10. This raised the question of whether the same configuration is measured, or if the H center may involve an additional defect [19,20].Here, we report a case where the same configuration can be established for H and Mu. We compare the hfi of the μSR experiment with the proton-ENDOR result, both for rutile TiO 2 . The H center in TiO 2 was extensively studied by Brant et al.[21] using electron paramagnetic resonance (EPR) and ENDOR, who found that the electron is located at the Ti ion reducing it from Ti 4+ to Ti 3+ . H is bound to one of the six O atoms surrounding Ti and the magnetic interaction between the proton and the electron is mainly dipolar. This specific hfi permits a sensitive comparison of the two experiments. We have observed a dramatic change of the μSR spectra with increasing temperature and a complete disappearance of the hyperfine splitting at 10 K. We show that this is due to rapid jumps of the muon between neighboring bonding positions to O atoms around Ti 3+ . The very strong angle dependence of the dipolar interaction and the averaging over values in different * ruivilao@fis.uc.pt positions lead to the reduction and final disappearance of the hfi...

show abstract

Hydrogen impurity in yttria:Ab initioandμSR perspectives

Cited by 35 publications

References 57 publications

Isolated hydrogen configurations in zirconia as seen by muon spin spectroscopy andab initiocalculations

Isolated hydrogen configurations in zirconia as seen by muon spin spectroscopy andab initiocalculations

Elastic and electronic properties of partially ordered and disordered Zr(C1−N ) solid solution compounds: A first principles calculation study

Muonium donor in rutileTiO2and comparison with hydrogen

Contact Info

Product

Resources

About