Structural, magnetic and dielectric properties of Sc modified (1 − y)BiFeO3–yBaTiO3 ceramics

doi:10.1016/j.solidstatesciences.2011.08.001

Solid State Sciences

Volume 13, Issue 10, October 2011, Pages 1885-1888

https://doi.org/10.1016/j.solidstatesciences.2011.08.001 Get rights and content

Abstract

In this study, the bulk ceramics with general formula (1 − y)BiFe_1−xSc_xO₃–yBaTiO₃ (x = 0.1–0.3, y = 0.1–0.3 mol%) were prepared by the traditional solid-state method. Their structural, magnetic, dielectric properties were investigated. X-ray diffraction analysis indicated that all samples crystallized in pure perovskite structure. The structural phase transition from R3c to Pm-3m occurred when the amount of BaTiO₃ exceeded 20 mol%. The room temperature M–H curves were obtained and scandium doping could decrease the magnetic coercive field. Thus the soft magnetic property of prepared solid solutions could be improved. Frequency dependence of dielectric constant and loss were studied. The results indicated that addition of an appropriate amount of scandium could reduce the dielectric loss. The dielectric losses of 0.7BiFe_1−xSc_xO₃–0.3BaTiO₃ (x = 0, 0.1, 0.2, 0.3) at 1 kHz were 0.104, 0.094, 0.043 and 0.057 respectively.

Graphical abstract

Highlights

► Solid solutions with general formula (1 − y)BiFe_1−xSc_xO_3−yBaTiO₃ (x = 0.0−0.3, y = 0.1−0.3 mol%) were prepared. ► Being different from dopants commonly used in bismuth ferrite solid solution, scandium was used as dopant in this study. ► Scandium doping has improved magnetic property of prepared solid solutions, and the addition of an appropriate amount of scandium could reduce the dielectric loss.

Introduction

Multiferroics have received much attention in recent years since they exhibit simultaneously antiferromagnetic and antiferroelectric order in the same phase [1], [2], and therefore offer great potential for applications in multiple state memory elements, electric field controlled ferromagnetic resonance devices and transducers with magnetically modulated piezoelectricity [3], [4], [5]. However, it is difficult to find materials that are both ferroelectric and magnetic because that the difference in filling of the d shells required for ferroelectricity and magnetism makes these two ordered states mutually exclusive [6].

BiFeO₃ (BFO) is a promising candidate as multiferroic material. It has a rhombohedrally distorted perovsikte structure with Neel temperature of 370 °C and Curie temperature of 830 °C. Preparation of single-phase BFO is difficult due to the narrow temperature range of phase stabilization, spurious phases such as Bi₂Fe₄O₉, Bi₂₅FeO₄₀ or Bi₃₆Fe₂₄O₅₇ often mix with it [7], [8]. Several methods have been reported to obtain pure BFO, including calcination followed by leaching with nitric acid [9], rapid liquid phase sintering technique [10] and forming solid solution of BFO with other ABO₃ type perovskites such as PbTiO₃, PZT, and BaTiO₃ [11], [12], [13], [14].

Till now BiFeO₃–BaTiO₃ (BFO–BTO) solid solution has been fully investigated because it is lead-free and has improved electrical properties of BFO. To further enhance overall properties of BFO, doping methods have been applied. Liu [15] and Leontsev [16] have investigated BFO–BTO solid solutions modified by Cr and Mn, respectively.

In addition to Cr and Mn, Sc is another choice for substitution of Fe. Shannigrahi [17] have reported enhanced overall magnetic properties of Sc modified BFO thin film and they ascribed this improvement to scandium’s non-magnetic nature, which would change the balance of up and down spins of Fe²⁺ and Fe³⁺. Therefore it is meaningful to study on Sc modified BFO–BTO solid solutions.

Section snippets

Sample preparation

(1 − y)BiFe_1−xSc_xO₃–yBaTiO₃ (y = 0.1–0.3; x = 0–0.3) solid solutions (abbreviated as BFS_xO–yBTO) were fabricated by the conventional solid-state reaction method. Analytical-grade raw materials, Bi₂O₃, Fe₂O₃, Sc₂O₃, BaCO₃ and TiO₂ were weighed and mixed in a ball mill for 10 h using alcohol as the milling media. After drying, the powders were pre-sintered at 830 °C for 8 h in air and then taken out and ground in an agate mortar for half an hour. The resultant powders were pressed into disks 11 mm in

Structure of all prepared samples

X-ray diffraction patterns of BFS_xO–yBTO solid solutions at room temperature are given in Fig. 1. All samples are found to be single-phase and no spurious phases are observed, which indicate that the formation of solid solution can eradicate unfavorable phases. Their corresponding crystal structures are refined from X-ray powder diffraction data by Rietveld method using Fullprof 2009. The refinement results indicate the BFS_xO–yBTO system maintains original R3c space group when x ≤ 20 mol% and the

Conclusion

Scandium doped BFO–BTO solid solutions were successfully prepared by the conventional solid reaction route. Fullprof 2009 software was used to calculate structural information and the results showed that the transition of rhombohedral symmetry to cubic symmetry was found in BFO–yBTO system when 20 mol% < y < 30 mol%. The replacement of magnetic element Fe by proper amount of scandium (unchanged valence) can simultaneously decrease magnetic coercive field and spontaneous magnetization slightly. Thus

Acknowledgment

This work was financially supported by National Natural Science Foundation of China (21072221, 11075220) and the National Basic Research Program of China (973 Program) 2010CB833101.

References (23)

M.T. Buscaglia et al.
J. Eur. Ceram. Soc.
(2006)
J.R. Sahu et al.
Solid State Sci.
(2007)
J. Wang et al.
Science
(2003)
M. Fiebig et al.
Nature
(2002)
C.W. Nan et al.
J. Am. Ceram. Soc.
(1997)
J. Ryu et al.
J. Electroceram.
(2002)
T. Kanai et al.
Adv. Mater.
(2001)
S.W. Cheong et al.
Nat. Mater.
(2007)
R. Palai et al.
Phys. Rev. B
(2008)
M. Kumar et al.
J. Appl. Phys.
(2006)

M.M. Kumar et al.

Appl. Phys. Lett.

(2000)

Cited by (17)

Materials and features of ferroelectric photocatalysts: The case of multiferroic BiFeO<inf>3</inf>
2021, Photocatalytic Systems by Design: Materials, Mechanisms and Applications
Ferroelectric perovskite materials are of considerable interest in the field of photocatalysis. To date, several iron-based photocatalytic materials are developed and explored its multifunctional applications for energy, environment, and health care applications. This chapter endeavors to give an overview on emerging material BiFeO₃. Tuning of optical, structural, and morphological properties of BiFeO₃ facilitated enhanced photocatalytic efficiency. This study focused on the effect of individual d-block dopants and their multifunctional behavior on parameters such as grain size, morphology, and charge carrier recombination. This chapter also provides inputs for future research work directed towards the synthesis of efficient and stable photocatalysts for green energy production via water splitting.
Improved ferroelectric properties of BiFeO<inf>3</inf>-based piezoelectric ceramics through morphotropic phase boundary construction
2020, Ceramics International
The ceramic (1-x)BiFe_0.985Sc_0.015O₃-xBaZr_0.2Ti_0.8O₃ + 1mol% MnO₂ (x = 0.20, 0.25, 0.30, 0.35) (BFS-xBZT) was synthesized using the traditional ceramic sintering method. The components of the ceramic were determined by constructing a morphotropic phase boundary (MPB) which consists of rhombohedral (R) and tetragonal (T) phases (0.24≤ x ≤ 0.26). With the accumulation of BZT content, relax behaviors were observed by dielectric properties measurements. At the MPB, the crystal structures of the R phase and T phase change abruptly. The distortion degree of the R phase increases, and the differences between a and c of the T phase decrease. An enhanced ferroelectricity Pr of ~27.8 μC/cm² and apex piezoelectric coefficient d₃₃ of 131 ± 4 pC/N are obtained near the MPB (x = 0.25), due to the R-T phase coexistence near room temperature. The results show that BFS-xBZT ceramics could be a candidate for lead-free piezoelectric ceramics at high operating temperatures.
Multiferroic bismuth ferrite-based materials for multifunctional applications: Ceramic bulks, thin films and nanostructures
2016, Progress in Materials Science
Citation Excerpt :
Since then, BFO, in its various forms such as ceramic bulks, thin films, and nanostructures, have been extensively studied. Many interesting findings have therefore been reported [23–764]. For example, the Pr value can exceed >150 μC/cm2 in BFO-based thin films, as result of the substrate or lattice strain, composition tuning, and effect of buffer layer [5,23,48,78,349].
Among the different types of multiferroic compounds, bismuth ferrite (BiFeO₃; BFO) stands out because it is perhaps the only one being simultaneously magnetic and strongly ferroelectric at room temperature. Therefore, in the past decade or more, extensive research has been devoted to BFO-based materials in a variety of different forms, including ceramic bulks, thin films and nanostructures. Ceramic bulk BFO and their solid solutions with other oxide perovskite compounds show excellent ferroelectric and piezoelectric properties and are thus promising candidates for lead-free ferroelectric and piezoelectric devices. BFO thin films, on the other hand, exhibit versatile structures and many intriguing properties, particularly the robust ferroelectricity, the inherent magnetoelectric coupling, and the emerging photovoltaic effects. BFO-based nanostructures are of great interest owing to their size effect-induced structural modification and enhancement in various functional behaviors, such as magnetic and photocatalytic properties. Although to date several review papers on BFO and BFO-based materials have been published, they were each largely focused on one particular form of BFO. There have been very few papers addressing the different forms of BFO in a comprehensive manner and providing a comparison across the different forms. As BFO has been extensively studied over the past more than one decade especially in the past several years, there have been new phenomena arising more recently. Naturally they were not included in the early reviews. Here, we provide an updated comprehensive review on the progress of BFO-based materials made in the past fifteen years in the different forms of ceramic bulks, thin films and nanostructures, focusing on the pathways to modify different structures and to achieve enhanced physical properties and new functional behavior. We also prospect the future potential development for BFO-based materials in the cross disciplines and for multifunctional applications. We hope that this comprehensive review will serve as a timely updating and reference for researchers who are interested in further exploring bismuth ferrite-based materials.
Compositional dependence of dielectric and ferroelectric properties in BiFeO<inf>3</inf>-BaTiO<inf>3</inf> solid solutions
2014, Ceramics International
Citation Excerpt :
In spite of the potential technical importance of BiFeO3–BaTiO3 ceramics in piezoelectric applications, their dielectric and ferroelectric properties are still not well understood. While magnetic properties have been extensively measured in BiFeO3–BaTiO3 solid solutions [2,7–12], the dielectric and ferroelectric properties are relatively less investigated, with the sparsely reported results showing significant variations between investigations. Furthermore, misunderstanding with some transition temperatures in BiFeO3–BaTiO3 occurs widely.
Polycrystalline (1−x)BiFeO₃–xBaTiO₃ (0.11≤x≤0.5) ceramics have been prepared by the solid-state reaction method to investigate their phase structure, dielectric, ferroelectric, and field-induced strain behaviors. The phase was found to change from rhombohedral in BiFeO₃-rich compositions to pseudocubic at a BaTiO₃ content of x=0.33. The room-temperature dielectric permittivity increased with increasing BaTiO₃ content regardless of phase structure, except for a small dielectric permittivity peak additionally observed at x=0.33. The (1−x)BiFeO₃–xBaTiO₃ solid solutions displayed a maximum in permittivity at temperatures (T_m) above 300 °C in the compositional range of 0.2≤x≤0.5. The frequency dependence of high-temperature dielectric properties suggests that BiFeO₃–BaTiO₃ is a relaxor ferroelectric. Normal ferroelectric loops and large electric field-induced strains were observed for the BiFeO₃–BaTiO₃ ceramics. The BiFeO₃–BaTiO₃ shows a promising candidate for high temperature ferroelectric applications.
Microstructure, ferroelectric and piezoelectric properties of Bi<inf>0.5</inf>K<inf>0.5</inf>TiO<inf>3</inf>-modified BiFeO<inf>3</inf>-BaTiO<inf>3</inf> lead-free ceramics with high Curie temperature
2013, Journal of the European Ceramic Society
The effects of composition, sintering temperature and dwell time on the microstructure and electrical properties of (0.75 − x)BiFeO₃–0.25BaTiO₃–xBi_0.5K_0.5TiO₃ + 1 mol% MnO₂ ceramics were studied. The ceramics sintered at 1000 °C for 2 h possess a pure perovskite structure and a morphotropic phase boundary of rhombohedral and pseudocubic phases is formed at x = 0.025. The addition of Bi_0.5K_0.5TiO₃ retards the grain growth and induces two dielectric anomalies at high temperatures (T₁ ∼ 450–550 °C and T₂ ∼ 700 °C, respectively). After the addition of 2.5 mol% Bi_0.5K_0.5TiO₃, the ferroelectric and piezoelectric properties of the ceramics are improved and very high Curie temperature of 708 °C is obtained. Sintering temperature has an important influence on the microstructure and electrical properties of the ceramics. Critical sintering temperature is 970 °C. For the ceramic with x = 0.025 sintered at/above 970 °C, large grains, good densification, high resistivity and enhanced electrical properties are obtained. The weak dependences of microstructure and electrical properties on dwell time are observed for the ceramic with x = 0.025.
Effect of Zr<sup>4+</sup> substitution on thermal stability and electrical properties of high temperature BiFe<inf>0.99</inf>Al<inf>0.01</inf>O <inf>3</inf>-BaTi<inf>1-x</inf>Zr<inf>x</inf>O<inf>3</inf> ceramics
2013, Journal of Alloys and Compounds
Citation Excerpt :
Therefore, The Pb-free ceramics with excellent piezoelectric properties and high depolarization temperature (Td ⩾ 300 °C) are the only feasible solution. Till now, BiFeO3–BaTiO3(BF–BT) solid solution has been fully investigated, because it is lead-free and has high Curie temperature Tc = ∼450 °C and high depolarization temperature Td = ∼400 °C and favorable piezoelectric constant d33 = ∼130 pC/N at MPB [6–9]. Recently, Yang et al. reported that (1−x)BiFeO3–xBaTiO3 ceramics exhibited optimum electrical properties of d33 = 136 pC/N, kp = 0.312 and good temperature stability of Tc = 485 °C, Td = 420 °C at the MPB composition x = 0.275 [10].
High-temperature Pb-free ceramics of 0.72BiFe_0.99Al_0.01O₃–0.28BaTi₁₋_xZr_xO₃ (BFA–BZ_xT) have been prepared through solid state reaction route. The influence of the Zr⁴⁺ substitution for Ti⁴⁺ on microstructure, thermal stability and electrical properties of the BFA–BZ_xT ceramics was investigated. The results showed single-phase solid solutions occurred for compositions x = 0–0.12 and a morphotropic phase boundary (MPB) separating rhombohedral and pseudocubic phases existed near x = 0.03. The substitution of Zr⁴⁺ for Ti⁴⁺ caused significant change of grain size for BFA–BZ_xT ceramics. The optimum piezoelectric properties of d₃₃ = 157 pC/N, k_p = 0.33, combined with improved depoling temperature T_d = 425 °C, are obtained around the MPB composition of x = 0.03. The results indicate that BFA–BZ_xT ceramics have a great potential to apply in high temperature field.

View all citing articles on Scopus

View full text

Structural, magnetic and dielectric properties of Sc modified (1 − y)BiFeO3–yBaTiO3 ceramics

Abstract

Graphical abstract

Highlights

Introduction

Section snippets

Sample preparation

Structure of all prepared samples

Conclusion

Acknowledgment

J. Eur. Ceram. Soc.

Solid State Sci.

Science

Nature

J. Am. Ceram. Soc.

J. Electroceram.

Adv. Mater.

Nat. Mater.

Phys. Rev. B

J. Appl. Phys.

Appl. Phys. Lett.

Structural, magnetic and dielectric properties of Sc modified (1 − y)BiFeO₃–yBaTiO₃ ceramics