Structure, Ferroelectric, Piezoelectric, and Ferromagnetic Properties of BiFeO₃‐BaTiO₃‐Bi_0.5Na_0.5TiO₃ Lead‐Free Multiferroic Ceramics

Abstract

Lead‐free multiferroic ceramics of BiFeO3‐BaTiO3‐Bi0.5Na0.5TiO3 have been prepared by a conventional ceramic technique. The microstructure, multiferroic, and piezoelectric properties of the ceramics have been studied. The ceramics sintered at 1000°C for 2 h possess a pure perovskite structure and a morphotropic phase boundary of rhombohedral and tetragonal phases is formed at x = 0.02. After the addition of Bi0.5Na0.5TiO3, two dielectric anomalies are observed at high temperatures (Tm ~ 510°C–570°C and T2 ~ 720°C). The phase transition around Tm becomes wider gradually with increasing x. The ferroelectricity, piezoelectricity, and ferromagnetism of the ceramics are significantly improved after the addition of Bi0.5Na0.5TiO3. High resistivity (~1.3 × 109 Ω·cm), strong ferroelectricity (Pr = 27.4 μC/cm2), good piezoelectricity (d33 =140 pC/N, kp = 31.4%), and weak magnetic properties (Mr =0.19 emu/g) are observed.

BiFeO3-BaTiO3: A new generation of lead-free electroceramics

“…[68][69][70] In each case, oxygen vacancies (V O Þ are generated. To resolve these issues in BF-BT, excess Bi 2 O 3 is added to compensate for volatilisation [71][72][73] and/or dopants [74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90] are used to accommodate changes in local defect chemistry associated with the multiple valence state of Fe. Dopants in the field of piezoelectric materials are classified into three groups: donor (higher valence), acceptor (lower valence) and self-compensated (average valence number remains the same).…”

Ultrasonic Transducer Fabricated Using Lead-Free BFO-BTO+Mn Piezoelectric 1-3 Composite

“…Therefore, the lead-free ceramics were used in various applications, such as ultrasonic transducers [6][7][8][9], pyroelectric sensors [10] and actuators [11,12]. BFO-BTO system is proposed to be an important family of high-performance lead-free piezoelectric ceramics because of its good ferroelectric properties [13][14][15][16][17]. Additionally, Mn doping is a common method to enhance the piezoelectric properties and reduce the dielectric loss of the piezoelectric materials [15,16], thus, Mn modified BFO-BTO ceramic with good ferroelectric properties was chosen for transducer applications.…”

B‐site‐doped BiFeO3‐based piezoceramics with enhanced ferro/piezoelectric properties and good temperature stability

“…In order to ascertain the phase structures, the XRD peaks ranging from 38°‐40° (111) and 45°‐46° (200) were fitted with the Peakfit software, as shown in Figure 1B and 1C. The peaks between 38.5° and 39.5° were fitted into (202) R , (006) R , and (111) T peaks, the peaks between 45° and 46° were fitted into (002) T , (200) R , and (200) T peaks, where R and T represented rhombohedral and tetragonal phases, respectively, indicating coexistences of the R and T phases in the BFM‐BT ceramics 15 …”