Gadolinium ion pairs in Pb5Ge3O11: EPR investigation

Vazhenin, V. A.; Потапов, А. П.; Artyomov, M. Yu.

doi:10.1134/s1063783415040319

Cited by 2 publications

(2 citation statements)

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“…%. The broad lines on the EPR spectra of TiO 2 samples doped with magnetic 3d ions were previously reported in refs. − It was suggested that these lines may originate from the AFM clusters formed by 3d magnetic ions coupled by negative exchange interaction. Another possible origin of the broad lines on the EPR spectra of the Fe doped TiO 2 is emergence of the hematite-based magnetic impurity phase as it was discussed in ref .…”

Section: Experimental Results and Discussionsupporting

confidence: 71%

Formation of Fe–Fe Antiferromagnetic Dimers in Doped TiO₂:Fe Nanoparticles

et al. 2018

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In this work, we report the results of comprehensive experimental and theoretical study of magnetic properties of TiO 2 nanoparticles (20 nm) doped with Fe at various concentrations ranging from 0.1 to 4.6 at. %. Our electron paramagnetic resonance and magnetic measurements data evidence the mixed magnetic state, where paramagnetic Fe 3+ ions coexist with short-range antiferromagnetic correlations caused by negative exchange interaction between neighboring Fe 3+ ions. A quantum mechanical model of the Fe-based magnetic cluster represented as a set of dimers with strong ∼(100−300) K and weak (∼1 K) exchange interactions has been proposed. Our model was found to provide a good description of magnetic properties of TiO 2 :Fe nanopowders. Density-functional theory (DFT) calculations revealed Fe 3+ oxidation state of the iron center in the vicinity of an oxygen vacancy in the crystal structure of anatase. DFT calculations confirmed that two types of Fe 3+ spin-pairs with weak and strong exchange interactions can be formed in the vicinity of an oxygen vacancy. Accumulation of magnetic moment carriers and formation of magnetic clusters in TiO 2 nanoparticles with anatase structure were found to be a general tendency for all studied TiO 2 :Fe nanopowders.

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Section: Experimental Results and Discussionsupporting

confidence: 71%

Formation of Fe–Fe Antiferromagnetic Dimers in Doped TiO₂:Fe Nanoparticles

et al. 2018

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“…[ 33–38 ] The broad lines in the EPR spectra of

{TiO}_{2}

samples doped with magnetic

3 d

ions were previously reported. [ 39–45 ] It was suggested that these broad lines can arise from AFM clusters formed by 3 d magnetic ions coupled by negative exchange interaction or Fe–Fe AFM dimers. [ 18 ]…”

Section: Resultsmentioning

confidence: 99%

Magnetic Properties, Electron Paramagnetic Resonance, and Photoelectron Spectroscopy Studies of Nanocrystalline TiO₂ Co‐Doped with Al and Fe

Yermakov

Galakhov

Minin

et al. 2020

Physica Status Solidi (b)

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Electron paramagnetic resonance, X‐ray photoelectron spectroscopy, field dependence of magnetization, X‐ray diffraction, and transmission electron microscopy are applied for the characterization of Al‐doped TiO2 nanopowders with Fe impurities synthesized by the autoclave‐assisted hydrothermal method and annealed in vacuum or in hydrogen. The sizes of the TiO2:(Al, Fe) nanoparticles are estimated to be about 10–20 nm. It is proposed that Al ions are presumably placed in the TiO2 lattice in interstitial positions. Moreover, Fe3+ ions can occupy tetrahedral positions of Ti4+ ions as a result of Al‐doping. The results suggest that Al‐doped TiO2 nanopowders with Fe impurities annealed in vacuum or hydrogen display both intrinsic and extrinsic ferromagnetic properties.

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Gadolinium ion pairs in Pb5Ge3O11: EPR investigation

Cited by 2 publications

References 12 publications

Formation of Fe–Fe Antiferromagnetic Dimers in Doped TiO₂:Fe Nanoparticles

Formation of Fe–Fe Antiferromagnetic Dimers in Doped TiO₂:Fe Nanoparticles

Magnetic Properties, Electron Paramagnetic Resonance, and Photoelectron Spectroscopy Studies of Nanocrystalline TiO₂ Co‐Doped with Al and Fe

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Gadolinium ion pairs in Pb5Ge3O11: EPR investigation

Cited by 2 publications

References 12 publications

Formation of Fe–Fe Antiferromagnetic Dimers in Doped TiO2:Fe Nanoparticles

Formation of Fe–Fe Antiferromagnetic Dimers in Doped TiO2:Fe Nanoparticles

Magnetic Properties, Electron Paramagnetic Resonance, and Photoelectron Spectroscopy Studies of Nanocrystalline TiO2 Co‐Doped with Al and Fe

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Product

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Formation of Fe–Fe Antiferromagnetic Dimers in Doped TiO₂:Fe Nanoparticles

Formation of Fe–Fe Antiferromagnetic Dimers in Doped TiO₂:Fe Nanoparticles

Magnetic Properties, Electron Paramagnetic Resonance, and Photoelectron Spectroscopy Studies of Nanocrystalline TiO₂ Co‐Doped with Al and Fe