A comparative study on structural, dielectric and multiferroic properties of CaFe2O4/BaTiO3 core-shell and mixed composites

et al. 2019

J. Phys. Commun.

Magnetoelectric composites have attracted much attentions due to their excellent multiferroic properties at room temperature. In this paper, CoFe 2 O 4 -PbZr 0.52 Ti 0.48 O 3 (CFO-PZT) composite ceramics with different molar ratios (CFO/PZT=1:4, 1:5, 1:6 and 1:7) were prepared by conventional solid reaction method. Effects of molar ratio on the structure, dielectric, ferroelectric and magnetic properties were comparatively investigated. X-ray diffraction patterns confirmed biphase structures of the composites, which can be indexed as CFO and PZT, no other obvious phase can be found with the limitation of the XRD resolution. Scanning electron microscopy (SEM) images show that the surface of the prepared samples is not dense enough and many pores are formed, the mean grain size is about 200 nm. The same relaxation behavior was observed in the intermediate temperature range of PZT-CFO composite ceramics. At room temperature, the dielectric constant and dielectric loss of the specimen 1:4 are the highest. The leakage current of the sample 1:4 is the lowest while the sample 1:6 has the largest value. As the CFO content in the composite decreases, both the saturation (Ms) and the remnant (Mr) magnetization decrease. Among them, the sample 1:4 presents better ferroelectric and magnetic properties, the remnant polarization is 1.13 μC cm −2 , the saturation magnetization and remnant magnetization are 11.01 and 3.28 emu g −1 , respectively. The sample 1:6 has the largest coercive field (945.27 Oe) while the sample 1:7 show the smallest value (681.19 Oe). Interface interaction between CFO/PZT may be applied to explain this phenomenon.

Section: Ferroelectric Propertiesmentioning

confidence: 78%

Section: Introductionmentioning

confidence: 99%

A comparative study on the structural, dielectric, ferroelectric and magnetic properties of CoFe₂O₄/PbZr_0.52Ti_0.48O₃ multiferroic composite with different molar ratios

et al. 2019

J. Phys. Commun.

“…All the composites show typical B-H loops and saturated behavior above 4000 G at room temperature in Fig. 3b, suggesting the presence of an ordered magnetic structure in the composites [16]. The saturated magnetization (M s ) and remanent magnetization (M r ) increase slightly after Mn-ion doping [17].…”

Section: Ferroelectricmentioning

confidence: 91%

“…1 Introduction Multiferroic materials are becoming a research hotspot recently due to their fascinating physical prosperities and promising applications [1,2]. Compared to single-phase materials [3,4], composite multiferroic materials show a much larger magnetoelectric effect and they are considered as a promising candidate for multiferroic materials.…”

mentioning

confidence: 99%

Enhanced resistivity impact on the magnetoelectric properties of diphase multiferroic BaTiO₃–BaFe_12−xMn_xO₁₉ composite ceramics

Physica Rapid Research Ltrs

Wei

et al. 2017

The multiferroic magnetoelectric composites have attracted great interest due to some new expected physics and wide practical applications. However, the low resistivity restricts their further applications. In this work, multiferroic 0.8BaTiO 3 -0.2BaFe 12-x Mn x O 19 composite ceramics were prepared by microwave-hydrothermal and microwave-sintering methods. It was found that the dielectric constant of the composites increased with increasing x, while the resistivity increased gradually. Accordingly, the dielectric loss dropped as expected and the P-E loops showed slimmer shapes after introducing of Mn ions. In addition, the magnetic hysteresis loops of the composite ceramics prepared showed an excellent ferromagnetic behavior. In summary, smaller leakage current and slim P-E loops were obtained through Mn ion doping in BaFe 12 O 19 and forming BaTiO 3 -BaFe 12Àx Mn x O 19 composite ceramics while maintaining their good ferromagnetic property successfully.

“…For example, Fe 3 O 4 , MFe 2 O 4 (M = Mg, Ca, Mn, Co, Ni, Cu, Zn, etc.) and (La,Ca)MnO 3 are usually chosen as the magnetic phase while BiFeO 3 , (Ba,Sr)TiO 3 , Ba(Zr,Ti)O 3 and Pb(Zr,Ti)O 3 have been used as the ferroelectric phase [17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Influence of molar ratio on dielectric, ferroelectric and magnetic properties of Co0.5Mg0.5Fe2O4/Ba0.85Sr0.15TiO3 composite ceramics

Liu

Zhang

et al. 2019

PAC

In the present work, Co 0.5 Mg 0.5 Fe 2 O 4 /Ba 0.85 Sr 0.15 TiO 3 (CMFO/BST) composite ceramics with different molar ratios (1:1, 1:2, 1:4, 1:6 and 1:8) were prepared by sol-gel method and sintered at 1150°C. The effects of molar ratio on the structure, dielectric and multiferroic properties were comparatively studied. The results indicate that all the synthesized composites mainly show bi-phase structure except slight presence of impurity phases. The surface of the specimens is relatively dense and the mean grain size is about 2 µm. It decreases at first and then increases with the increased molar ratio. The dielectric constant shows decreased trend with increasing the molar ratio, while the dielectric loss presents the opposite behaviour. With the increase of molar ratio, the height of the relaxation peak decreases while the peak position shifts to higher temperature range. The relaxation peak evolves gradually from one to two peaks. The residual polarization increases with voltage but decreases with frequency. The maximal polarization of 1.28 µC/cm 2 is obtained in the specimen with the molar ratio of 1:8, due to the largest concentration of ferroelectric phase BST. The magnetization shows abnormal behaviour with the change in molar ratio. The largest saturation and remnant magnetization are 20.89 and 12.66 emu/g, respectively when the molar ratio is 1:2 due to the stronger interface interaction effect between the two phases.