Large difference between the magnetic properties of Ba and Ti co-doped BiFeO₃bulk materials and their corresponding nanoparticles prepared by ultrasonication

Abstract

The ceramic pellets of the nominal compositions Bi0.7Ba0.3Fe1−xTixO3 (x = 0.00-0.20) were prepared initially by standard solid state reaction technique. The pellets were then ground into micrometer-sized powders and mixed with isopropanol in an ultrasonic bath to prepare nanoparticles. The X-ray diffraction patterns demonstrate the presence of a significant number of impurity phases in bulk powder materials. Interestingly, these secondary phases were completely removed due to the sonication of these bulk powder materials for 60 minutes. The field and temperature dependent magnetization measurements exhibited significant difference between the magnetic properties of the bulk materials and their corresponding nanoparticles. We anticipate that the large difference in the magnetic behavior may be associated with the presence and absence of secondary impurity phases in the bulk materials and their corresponding nanoparticles, respectively. The leakage current density of the bulk materials was also found to suppress in the ultrasonically prepared nanoparticles compared to that of bulk counterparts.

Low temperature synthesis of BiFeO3nanoparticles with enhanced magnetization and promising photocatalytic performance in dye degradation and hydrogen evolution

“…We have calculated the remanent magnetization (M r ) of the synthesized samples from the M-H hysteresis loops. 49,50 The maximum magnetization (M s ) at an applied magnetic eld of 13 kOe is also calculated from the hysteresis loops. Both M r and M s are higher for BFO nanoparticles prepared at 160 C hydrothermal reaction temperature.…”

Influence of the La3+, Eu3+, and Er3+ Doping on Structural, Optical, and Electrical Properties of BiFeO3 Nanoparticles Synthesized by Microwave-Assisted Solution Combustion Method

“…Recently, much attention has been paid to understand the effect of chemical composition [13][14][15][16], pressure [17,18], temperature of the synthesis, and annealing [19,20] on crystal structure and physical properties of BFO-based nanopowders. A number of studies reported strong dependence of BFO electromagnetic properties from its nanoscale structure [21,22].…”

Strong Impact of Cr Doping on Structural and Magnetic Properties of Bi0.5La0.5Fe1−xCrxO3−δ

“…Similar results have also been observed for other BFO-related materials. 26,56,57 For instance, the M(H) loops measured up to 60 kOe (6 T) for Sm/Nb-codoped BFO 56 or up to 9 T for Ca/Mncodoped BFO 58 could not reach magnetization saturation. On the other hand, Wang et al recently found that, with codoping of rare-earth and metal elements at Bi and Fe sites, respectively, the center of the M(H) loops became larger, weak ferromagnetism could be observed, and the magnetization increased substantially, indicating a transformation from an AFM to FM state.…”

“…The EB effect has also been observed in many other BFO-related materials with low-field M(H) loops. 57,59 The EB effect in the Bi 0.5 La 0.5 Fe 1Àx Cr x O 3Àd compounds originates from unidirectional exchange anisotropy due to the exchange coupling at interfaces between FM and AFM domains. It is worth noting that presence of long-range FM order was not detected by the NPD measurements, implying a short-range character of the FM phase in the samples.…”