Structural, optical, and magnetic properties of a new complex (1−x)Bi1/2Na1/2TiO3 + xMgNiO3−δ solid solution system

Dũng, Đặng Đức; Thoan, Nguyen Hoang; Dũng, Nguyễn Quốc; Lam, Nguyen Huu; Vinh, Pham Van; Lam, Vu Tien; Luong, Pham Dinh; Van, Duong Quoc

doi:10.1007/s00339-021-05255-5

Cited by 7 publications

(12 citation statements)

References 63 publications

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“…The previous study indicates that the Na‐ and Bi‐antisites in intrinsic rhombohedral BNT induce magnetism and dielectric properties, respectively 26 . In particular, Na‐antisite exhibits the p ‐type, while Bi‐antisite exhibits the n ‐type semiconductor 26 . In this study, we continually studied the BNT (110) surface with antisite defects.…”

Section: Resultsmentioning

confidence: 97%

“…The red dash circle denotes the site of atom‐antisite. The previous study indicates that the Na‐ and Bi‐antisites in intrinsic rhombohedral BNT induce magnetism and dielectric properties, respectively 26 . In particular, Na‐antisite exhibits the p ‐type, while Bi‐antisite exhibits the n ‐type semiconductor 26 .…”

Section: Resultsmentioning

confidence: 97%

“…Recently, Behara et al reported that intrinsic rhombohedral BNT exhibits both direct and indirect bandgap under strain. 26 The total density of states is shown in Figure 2B Furthermore, a peak at about -9 eV in the valence band was contributed by Bi 6s orbitals, which induces a large ferroelectric polarization for the BNT material. In the conduction band, the region closer to the Fermi-level is constructed from the Ti-3d orbitals, together with Bi-6p orbitals and a separated sub-level of Ti-4s orbitals.…”

Section: Resultsmentioning

confidence: 98%

“…There seems to be an indirect bandgap of 2.10 eV between valance band Q point and conduction band Z point. Recently, Behara et al reported that intrinsic rhombohedral BNT exhibits both direct and indirect bandgap under strain 26 . The total density of states is shown in Figure 2B for the perfect BNT (110) surface, and the red dash line shows the Fermi‐level (E F ).…”

Section: Resultsmentioning

confidence: 99%

“…On the BNT (110) Bi‐antisite band structure, as shown in Figure 5B, the Fermi‐level moves to the bottom of the conduction band, implying that it is an n ‐type semiconductor and has a greater conductivity. It should be noted that such a crossing of the Fermi‐level with the bottom of the conduction band does not imply real metallization because of the fact that there is still an energy excitation greater than the bandgap energy 25,26,29 …”

Section: Resultsmentioning

confidence: 99%

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Surface ferromagnetism of complex defects lead‐free ferroelectric Bi_0.5Na_0.5TiO₃ materials

Lam

Thoan

Trung

et al. 2022

Surface & Interface Analysis

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The complex surface defects induced magnetic properties of lead-free ferroelectric Bi 0.5 Na 0.5 TiO 3 (110) materials system are investigated by using the densityfunctional theory. Various types of surface defects were considered for calculation, including antisite, vacancies and interstitial defects. The calculated results indicated that a perfect Bi 0.5 Na 0.5 TiO 3 (110) surface produced zero magnetic moments. The conduction band was mostly contributed from Bi-6p and Ti-3d levels, where the valence band was built from O-2p. The antisite defects where Na replaced for Bi-site induced nonzero magnetic moments because of unsymmetrical spin O-2p up and O-2p down. While, the observation in nonzero magnetic moment of antisite defects Bi substitute for Na-site were originated from Ti-3d and Na-2s. The Na and Bi vacancies on the surface were tuned to the ferromagnetic because of the unsymmetrical contribution of O-2p, while the Ti and O vacancies were not. The Na and Bi surface interstitials induced the magnetic moments because of the contribution of the difference between Ti-3d and Bi-6p, respectively, while the Ti and O surface interstitials not induced the magnetic moments. We expected that our results could help to control chemical defects in new green multiferroic materials for smart electronic devices.

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Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 3 more Smart Citations

Surface ferromagnetism of complex defects lead‐free ferroelectric Bi_0.5Na_0.5TiO₃ materials

Lam

Thoan

Trung

et al. 2022

Surface & Interface Analysis

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Fe³⁺‐ and Nb⁵⁺‐Substituted Na_0.5Bi_0.5TiO₃: A Route toward Enhanced Ferroelectric Photovoltaic Response in Al/NBFNT/Ag Solar Cell through Reduced Bandgap and Controlled Oxygen Vacancy

Venkidu,

Raja,

Ruth

et al. 2023

Energy Tech

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Bulk ferroelectrics hold tremendous potential for the rapidly growing field of photovoltaic applications due to the separation of charge carriers caused by polarization, resulting in a high photovoltage. However, the wider bandgap in ferroelectrics limits their photoresponse. Attempts to tune the bandgap degrade ferroelectric polarization, while increased oxygen vacancy (V) in oxide perovskite hinders electron conduction and undermines ferroelectricity. Therefore, controlling V and maintaining polarization in reduced bandgap ferroelectric photovoltaics remains challenging. To address this, aliovalent Fe3+ and Nb5+ are co‐substituted on the B‐site of Na0.5Bi0.5TiO3 ceramics. Various techniques confirm the controlled V concentration, and UV‐absorption data reveal a reduction in bandgap energy from 3.01 to 2.38 eV through metal substitution. Density functional theory calculations identify a localized intermediate gap state within the bandgap, created by Fe–O hybridization, acting as a charge carrier scaffold and further reducing the bandgap energy to 2.47 eV. Remarkably, the Al/NBFNT75/Ag configuration achieves an augmented short‐circuit current density of 18.92 nA cm−2, while the open‐circuit voltage of the Al/NBFNT50/Ag device reaches 4.13 V. The resulting Al/NBFNT75/Ag device exhibits a maximum photovoltaic power density of 0.725 mW m−2 which is 9.5 times greater than Al/Na0.5Bi0.5TiO3/Ag. This approach successfully reduces V and achieves narrow bandgap conditions through suitable aliovalent substitution, leading to enhanced photovoltaic power, photosensing response, photoresponsivity, and specific detectivity.

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Optical properties of a new binary lead-free ferroelectric semiconductor Bi1/2Na1/2TiO3–Nd1/2Na1/2TiO3 solid solution system

et al. 2022

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Structural, optical, and magnetic properties of a new complex (1−x)Bi1/2Na1/2TiO3 + xMgNiO3−δ solid solution system

Cited by 7 publications

References 63 publications

Surface ferromagnetism of complex defects lead‐free ferroelectric Bi_0.5Na_0.5TiO₃ materials

Surface ferromagnetism of complex defects lead‐free ferroelectric Bi_0.5Na_0.5TiO₃ materials

Fe³⁺‐ and Nb⁵⁺‐Substituted Na_0.5Bi_0.5TiO₃: A Route toward Enhanced Ferroelectric Photovoltaic Response in Al/NBFNT/Ag Solar Cell through Reduced Bandgap and Controlled Oxygen Vacancy

Optical properties of a new binary lead-free ferroelectric semiconductor Bi1/2Na1/2TiO3–Nd1/2Na1/2TiO3 solid solution system

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Structural, optical, and magnetic properties of a new complex (1−x)Bi1/2Na1/2TiO3 + xMgNiO3−δ solid solution system

Cited by 7 publications

References 63 publications

Surface ferromagnetism of complex defects lead‐free ferroelectric Bi0.5Na0.5TiO3 materials

Surface ferromagnetism of complex defects lead‐free ferroelectric Bi0.5Na0.5TiO3 materials

Fe3+‐ and Nb5+‐Substituted Na0.5Bi0.5TiO3: A Route toward Enhanced Ferroelectric Photovoltaic Response in Al/NBFNT/Ag Solar Cell through Reduced Bandgap and Controlled Oxygen Vacancy

Optical properties of a new binary lead-free ferroelectric semiconductor Bi1/2Na1/2TiO3–Nd1/2Na1/2TiO3 solid solution system

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Surface ferromagnetism of complex defects lead‐free ferroelectric Bi_0.5Na_0.5TiO₃ materials

Surface ferromagnetism of complex defects lead‐free ferroelectric Bi_0.5Na_0.5TiO₃ materials

Fe³⁺‐ and Nb⁵⁺‐Substituted Na_0.5Bi_0.5TiO₃: A Route toward Enhanced Ferroelectric Photovoltaic Response in Al/NBFNT/Ag Solar Cell through Reduced Bandgap and Controlled Oxygen Vacancy