Effects of oxygen vacancies on the magnetic and electrical properties of Ca-substituted yttrium iron garnet

Song, Yi; Turpin, G. B.; Bornfreund, R. E.; Aoyama, Hideo; Wigen, P. E.

doi:10.1016/0304-8853(95)00580-3

Cited by 20 publications

(8 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The substitution of 0.3 Ca f.u. −1 was chosen to match the dopant concentration of the best p‐type YIG . At that concentration, the electrical resistivity of B(Ca 0.3 Y 0.2 )IG could be measured only above 450 K due to its high impedance values and reaches almost 4 × 10 3 Ω cm at that temperature.…”

Section: Resultsmentioning

confidence: 99%

“…Tetravalent cations such as Hf 4+ , Sn 4+ , and Si 4+ , were successfully substituted into the YIG lattice yielding n‐type semiconductors with electrical resistivity values between 10 3 and 10 5 Ω cm at room temperature. Conversely, divalent cationic substitutions such as Zn 2+ , Mg 2+ , Pb 2+ , or Ca 2+ in YIG yield p‐type semiconductors with electrical resistivities ranging from 10 7 to 10 3 Ω cm at 300 K; the best of them being comparable to the n‐doped YIG. For both n‐ and p‐type YIGs, impurities such as Pb 2+ , F − , or B 3+ (up to 0.1 f.u.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Atmosphere‐Induced Reversible Resistivity Changes in Ca/Y‐Doped Bismuth Iron Garnet Thin Films

Teurtrie

Popova

Koita

et al. 2019

Adv Funct Materials

View full text Add to dashboard Cite

Bismuth iron garnet Bi3Fe5O12 (BIG) is a multifunctional insulating oxide exhibiting remarkably the largest known Faraday rotation and linear magnetoelectric coupling. Enhancing the electrical conductivity in BIG while preserving its magnetic properties would further widen its range of potential applications in oxitronic devices. Here, a site‐selective codoping strategy in which Ca2+ and Y3+ substitute for Bi3+ is applied. The resulting p‐ and n‐type doped BIG films combine state‐of‐the‐art magneto‐optical properties and semiconducting behaviors above room temperature with rather low resistivity: 40 Ω cm at 450 K is achieved in an n‐type Y‐doped BIG; this is ten orders of magnitude lower than that of Y3Fe5O12. High‐resolution electron spectromicroscopy unveils the complete dopant solubility and the charge compensation mechanisms at the local scale in p‐ and n‐type systems. Oxygen vacancies as intrinsic donors play a key role in the conduction mechanisms of these doped BIG films. On the other hand, a self‐compensation of Ca2+ with oxygen vacancies tends to limit the conduction in p‐type Ca/Y‐doped BIG. These results highlight the possibility of integrating n‐type and p‐type doped BIG films in spintronic structures as well as their potential use in gas sensing applications.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Atmosphere‐Induced Reversible Resistivity Changes in Ca/Y‐Doped Bismuth Iron Garnet Thin Films

Teurtrie

Popova

Koita

et al. 2019

Adv Funct Materials

View full text Add to dashboard Cite

show abstract

“…In as-grown or low-temperature annealed Ca:YIG films, the magnetoresistance can be either positive or negative, which mainly depends on the direction of the applied field. In our microscopic model, it is explained as an effect of the orbital contributions to the magnetic moment which can be different in different eigen-states of the ionic clusters [1,4].…”

Section: L(r)mentioning

confidence: 99%

“…Iron-oxygen garnets, doped with divalent calcium ions (Ca:YIG) which donate compensating holes, offer a rare opportunity to produce semiconducting materials with permanent magnetic moments and a controlled number of the charge carriers [1]. Divalent diamagnetic ions substitute diamagnetic yttrium, which indirectly tailors also the magnitude and orientation of permanent magnetic moments attached to the clusters, while leaving magnetic cations unchanged.…”

Section: A Microscopic Model Of the Heterostructure And Its Magnetic mentioning

confidence: 99%

Spin‐polarized charge transport through ionic clusters of magnetic oxides

Gehring

Lehmann-Szweykowska

Wojciechowski

et al. 2005

Physica Status Solidi (b)

View full text Add to dashboard Cite

PACS 72.25. Mk, 75.50.Gg We analyze the spin-controlled charge transfer through a heterostructure consisting of one octahedral and one tetrahedral iron -oxygen ionic clusters, which are site-coupled, sharing an oxygen ion. A number of charge carriers can be manipulated by valence-uncompensated doping. The electron-energy structure of the clusters and that of the heterostructure are found on the basis of the Anderson model. Current -voltage (I-V) characteristics, derived from the Landauer-like formula, turn out to be highly sensitive to the position of the Fermi level. We also calculated the magnetoresistance for the heterostructure with different orientations of the magnetic field. The result confirmed the empirical data for Ca : YIG, which indicate strong anisotropy of the magnetoresistance. A microscopic model of the heterostructure and its magnetic propertiesIron-oxygen garnets, doped with divalent calcium ions (Ca:YIG) which donate compensating holes, offer a rare opportunity to produce semiconducting materials with permanent magnetic moments and a controlled number of the charge carriers [1]. Divalent diamagnetic ions substitute diamagnetic yttrium, which indirectly tailors also the magnitude and orientation of permanent magnetic moments attached to the clusters, while leaving magnetic cations unchanged. In our analysis, special attention will be focused on a role which the oxygen ions play in the charge transfer. One of our objectives is to show that the process is due to the p-d hybridization and can occur mostly via the oxygen ions. This suggestion remains in good agreement with the empirical data, and, it is confirmed by our previous theoretical results [2]. The heterostructure is attached to two reservoirs of the electrons. A control of the number of the charge carriers in the clusters can be maintained by assuming different positions of the Fermi level. We assume that all five 3d orbital states of Fe 3+ are occupied and, according to the Hund's rule, their respective spins are along the same direction. Thus, at either iron site, the angular momentum L is zero, whereas the net spin S is equal to 5 2 S = / . In case of O 2-, all six 2p spin-orbital states are occupied, and both the resultant orbital angular momentum and the resultant spin are equal to zero. In terms of orbital holes we start with vacuum at O 2-and five holes at each iron site. The available empirical data indicate that the charge transport in Ca:YIG is of the p-type. The Coulomb repulsion at the iron sites is limited to the strongest one between electrons in the same orbital eigen-states with mutually opposite spins. The on-site Coulomb repulsion, however, is neglected at the oxygen sites.

show abstract

“…Yttrium iron garnet (Y 3 Fe 5 O 12 , YIG) and its rare-earthsubstituted films have been progressively studied due to their wide potential applications, such as in telecommunication and magneto-optical devices [1]. Y site in YIG has been substituted with different materials such Bi, Ca, and Ce [2][3][4]. Bulk Tb-substituted YIG (Tb-YIG) has the potential in sensor application.…”

Section: Introductionmentioning

confidence: 99%

Effects of Annealing Temperature on Structure and Magnetic Properties of Tb_xY_3−xFe₅O₁₂ (x=0.2 and 0.4) Thin Films

Ibrahim

Aldbea

Abdullah

2012

Journal of Nanomaterials

View full text Add to dashboard Cite

Terbium-substituted yttrium iron garnet (TbxY3−xFe5O12(x=0.2and 0.4)) thin films have been successfully prepared by a sol-gel method followed by spin-coating process. The annealing of the films was performed at different temperatures like 700, 800, and900°Cand found that the films annealed at900°Cturned out to be crystallized into a pure garnet phase. All of the films were bearing grains of nanometer in size. Increasing the annealing temperature gave extra energy to the grains causing to be agglomerates. The lattice contraction occurred as the grain’s sizes were decreased due to the decrease of Fe2+formation. The magnetic measurements show that all of the films are soft magnetic materials with low saturation magnetization values. The hysteresis loops of the films which were annealed at900°Cwere found angular in shape similar to the single crystal-like YIG film.

show abstract

Effects of oxygen vacancies on the magnetic and electrical properties of Ca-substituted yttrium iron garnet

Cited by 20 publications

References 22 publications

Atmosphere‐Induced Reversible Resistivity Changes in Ca/Y‐Doped Bismuth Iron Garnet Thin Films

Atmosphere‐Induced Reversible Resistivity Changes in Ca/Y‐Doped Bismuth Iron Garnet Thin Films

Spin‐polarized charge transport through ionic clusters of magnetic oxides

Effects of Annealing Temperature on Structure and Magnetic Properties of Tb_xY_3−xFe₅O₁₂ (x=0.2 and 0.4) Thin Films

Contact Info

Product

Resources

About

Effects of oxygen vacancies on the magnetic and electrical properties of Ca-substituted yttrium iron garnet

Cited by 20 publications

References 22 publications

Atmosphere‐Induced Reversible Resistivity Changes in Ca/Y‐Doped Bismuth Iron Garnet Thin Films

Atmosphere‐Induced Reversible Resistivity Changes in Ca/Y‐Doped Bismuth Iron Garnet Thin Films

Spin‐polarized charge transport through ionic clusters of magnetic oxides

Effects of Annealing Temperature on Structure and Magnetic Properties of TbxY3−xFe5O12 (x=0.2 and 0.4) Thin Films

Contact Info

Product

Resources

About

Effects of Annealing Temperature on Structure and Magnetic Properties of Tb_xY_3−xFe₅O₁₂ (x=0.2 and 0.4) Thin Films