Enhancement of tetragonal anisotropy and stabilisation of the tetragonal phase by Bi/Mn-double-doping in BaTiO3 ferroelectric ceramics

Yabuta, Hisato; Tanaka, Hidenori; Furuta, Tatsuo; Watanabe, Takayuki; Kubota, Mamoru; Matsuda, Takanori; Ifuku, Toshihiro; Yoneda, Yasuhiro

doi:10.1038/srep45842

Cited by 26 publications

(9 citation statements)

References 53 publications

(53 reference statements)

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“…In order to calculate the magnetic moment per Mn ion and considering a high‐spin state, the Curie constant has been evaluated. The S quantum number is 5/2, 2, and 3/2 for the valence states of Mn 2+ , Mn 3+ , and Mn 4+ , respectively, in agreement with the fact that Mn ions doping the tetragonal phase acquire the Mn3+ valence state, thus the selected value for the S quantum number is 2. The Curie constant depends on the ion concentration and can be expressed as follows:

C false(x false) = x {normalC}_{0} = x N {(g {normalμ}_{normalB})}^{2} S false(normalS + 1 false) / 3 k_{normalB}

where g is the Landé g ‐factor, x = 1 is the atomic Mn concentration, N is the number of ions per unit volume, μ B the Bohr magneton, and k B is the Boltzmann constant.…”

Section: Resultssupporting

confidence: 70%

“…The Curie constant in our system (the inverse of the value of the slope of the straight line in the inset of Figure B) is C = 0.0182 emu K/Oe cm 3 . A recent report of bulk BaTiO 3 ceramics with a Mn concentration of 0.3% leads to C = 0.004858 emu K/Oe cm 3 . Additional values obtained in diluted systems with paramagnetic behavior are C = 0.04021 emu K/Oe cm 3 in Zn 0.95 Mn 0.5 O and C = 0.0201 emu K/Oe cm 3 in Zn 0.95 Co 0.5 O for sol‐gel prepared bulk samples; C = 0.01633 emu K/Oe cm 3 in In 2 SnO 5 :Mn at a 5 at.% thin films, and C = 0.0316 emu K/Oe cm 3 in Co 0.5 (Mg 0.55 Zn 0.45 ) 0.5 O 1− ν epitaxial thin films .…”

Section: Resultsmentioning

confidence: 95%

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Absence of ferromagnetism in ferroelectric Mn‐doped BaTiO₃ nanofibers

et al. 2018

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Pure and Mn-doped barium titanate nanofibers were synthesized by the electrospinning method. The morphology, microstructure and crystal structure of as-spun and annealed composite nanofibers were characterized by scanning electron microscopy and transmission electron microscopy. After annealing at 850°C, we obtain nanofibers a few μm long, formed by nanoparticles of irregular shape with sizes around 100 nm. X-ray diffraction and Raman spectroscopy show that a partial phase transition from tetragonal to hexagonal takes place for BaTi 0.90 Mn 0.10 O 3 . Vibrational phonon modes were calculated for BaTiO 3 within the density functional theory (DFT) framework. Ferroelectricity has been probed on pure and Mn-doped BaTiO 3 nanofibers, by means of piezoresponse force microscopy in an atomic force microscope, confirming the polar domain switching behavior of the fibers. The measured piezoelectric coefficient d 33 were 31 and 22 pm/V for BaTiO 3 and BaTi 0.90 Mn 0.10 O 3 . Magnetic properties of the samples were probed in a superconducting quantum interference device. Diamagnetic and paramagnetic behaviors were found in pure and Mn-doped samples, respectively. K E Y W O R D S atomic force microscopy, barium titanate, electrospinning, ferroelectricity/ferroelectric materials, perovskites

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C false(x false) = x {normalC}_{0} = x N {(g {normalμ}_{normalB})}^{2} S false(normalS + 1 false) / 3 k_{normalB}

where g is the Landé g ‐factor, x = 1 is the atomic Mn concentration, N is the number of ions per unit volume, μ B the Bohr magneton, and k B is the Boltzmann constant.…”

Section: Resultssupporting

confidence: 70%

Section: Resultsmentioning

confidence: 95%

Absence of ferromagnetism in ferroelectric Mn‐doped BaTiO₃ nanofibers

et al. 2018

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“…A decrease of oxygen vacancy content leads to an increase in the sample tetragonality ( c/a ), and thus, the observed ferroelectric polarization value. , On the other hand, increased substitution of a larger Ba ion by a relatively smaller Bi ion in tetragonal BTO phase adversely impacts the ferroelectric mode i.e. the Ti off-centric distortion, − and along with it the sample tetragonality. Thus, an interplay of these two counter forces (i.e., the reduction of oxygen-vacancy favoring the tetragonality and the substitution of Ba by smaller Bi ion opposing the tetragonality) is at work with increasing Bi doping in the BBTFO series, and as a result, the tetragonality of the unit cell first increases until x = 0.02 and, thereby, continues to decrease with further increase in x .…”

Section: Resultsmentioning

confidence: 99%

Toward an Enhanced Room-Temperature Photovoltaic Effect in Ferroelectric Bismuth and Iron Codoped BaTiO₃

et al. 2021

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Ferroelectric (FE) materials usually possess very high band gap (∼3–4 eV) and extremely poor electrical conductivity, which renders them unsuitable for photovoltaic applications. Here, we demonstrate that a carefully designed Bi–Fe codoped BaTiO3 (BTO) system (Ba1–x Bi x Ti0.9Fe0.1O3−δ, 0 ≤ x ≤ 0.10) provides a unique platform with the simultaneous optimization of low band gap, high FE polarization, and reasonable conductivity. We, thereby, find that the Jahn–Teller distortion associated with the doped transition metal ions, tetragonality (c/a), and oxygen vacancy content lead to such a controlled tuning of optical band gap, FE polarization, and electrical conductivity, respectively, over a wide range. While x = 0.00 (only Fe-doped) stabilizes in the undesirable paraelectric-hexagonal phase, x = 0.02 (Bi–Fe codoped) is engineered to possess a low band gap (∼1.55 eV), high FE polarization (∼5.2 μC/cm2) due to significant recovery of the FE tetragonal phase by more than 60%, and reasonably high electrical conductivity compared to BaTiO3, which cause it to exhibit the largest photovoltaic response within the series. Such an approach of optimizing the desired physical properties in a closely related mixed phase material where the ferroelectricity is engineered in the majority tetragonal BTO phase, while the minority hexagonal BTO phase aids in the reasonable conductivity (a combination that is not realizable in usual single phase FE materials), along with an optimum band gap, is promising in the realization of many more potential FE-based photovoltaic materials.

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“…Clearly, environmental (extrinsic) factors also play a role in the kinetics of the dissolution. Furthermore, while it has been shown that doping sometimes stabilize crystal structures [ 134 ], in general it induces instability that leads to higher dissolution and leaching of ions [ 135 ] that may be toxic [ 136 ]. NMs doping alters the band gap of the material compared to pristine NMs [ 122 ], which has been linked to oxidative stress in biological organisms when it overlaps with the redox potential for biological reactions [ 69 , 137 ].…”

Section: Resultsmentioning

confidence: 99%

Can an InChI for Nano Address the Need for a Simplified Representation of Complex Nanomaterials across Experimental and Nanoinformatics Studies?

et al. 2020

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Chemoinformatics has developed efficient ways of representing chemical structures for small molecules as simple text strings, simplified molecular-input line-entry system (SMILES) and the IUPAC International Chemical Identifier (InChI), which are machine-readable. In particular, InChIs have been extended to encode formalized representations of mixtures and reactions, and work is ongoing to represent polymers and other macromolecules in this way. The next frontier is encoding the multi-component structures of nanomaterials (NMs) in a machine-readable format to enable linking of datasets for nanoinformatics and regulatory applications. A workshop organized by the H2020 research infrastructure NanoCommons and the nanoinformatics project NanoSolveIT analyzed issues involved in developing an InChI for NMs (NInChI). The layers needed to capture NM structures include but are not limited to: core composition (possibly multi-layered); surface topography; surface coatings or functionalization; doping with other chemicals; and representation of impurities. NM distributions (size, shape, composition, surface properties, etc.), types of chemical linkages connecting surface functionalization and coating molecules to the core, and various crystallographic forms exhibited by NMs also need to be considered. Six case studies were conducted to elucidate requirements for unambiguous description of NMs. The suggested NInChI layers are intended to stimulate further analysis that will lead to the first version of a “nano” extension to the InChI standard.

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Enhancement of tetragonal anisotropy and stabilisation of the tetragonal phase by Bi/Mn-double-doping in BaTiO3 ferroelectric ceramics

Cited by 26 publications

References 53 publications

Absence of ferromagnetism in ferroelectric Mn‐doped BaTiO₃ nanofibers

Absence of ferromagnetism in ferroelectric Mn‐doped BaTiO₃ nanofibers

Toward an Enhanced Room-Temperature Photovoltaic Effect in Ferroelectric Bismuth and Iron Codoped BaTiO₃

Can an InChI for Nano Address the Need for a Simplified Representation of Complex Nanomaterials across Experimental and Nanoinformatics Studies?

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Enhancement of tetragonal anisotropy and stabilisation of the tetragonal phase by Bi/Mn-double-doping in BaTiO3 ferroelectric ceramics

Cited by 26 publications

References 53 publications

Absence of ferromagnetism in ferroelectric Mn‐doped BaTiO3 nanofibers

Absence of ferromagnetism in ferroelectric Mn‐doped BaTiO3 nanofibers

Toward an Enhanced Room-Temperature Photovoltaic Effect in Ferroelectric Bismuth and Iron Codoped BaTiO3

Can an InChI for Nano Address the Need for a Simplified Representation of Complex Nanomaterials across Experimental and Nanoinformatics Studies?

Contact Info

Product

Resources

About

Absence of ferromagnetism in ferroelectric Mn‐doped BaTiO₃ nanofibers

Absence of ferromagnetism in ferroelectric Mn‐doped BaTiO₃ nanofibers

Toward an Enhanced Room-Temperature Photovoltaic Effect in Ferroelectric Bismuth and Iron Codoped BaTiO₃