Enhanced Magnetodielectric Effect in Graded CoFe₂O₄/Pb(Zr_0.52Ti_0.48)O₃ Particulate Composite Films

Abstract

Graded particulate composite films in which ferromagnetic CoFe 2 O 4 nanoparticles are gradedly distributed in the ferroelectric Pb(Zr 0.52 Ti 0.48 )O 3 matrix along the thickness direction have been prepared on Pt/Ti/SiO 2 /Si wafers via sol-gel spincoating method and rapid annealing process. Compared with the homogenous films, the graded ones not only exhibited magnetic anisotropy, but also showed evident increase in both ferroelectric polarization and dielectric tunability. Moreover, great enhancement of magnetodielectric effect was observed in such graded films. We elucidated the origin of enhanced magnetodielectric coupling and attributed it to the combined influence of two factors, that is, the enhanced ferroelectric polarization caused by CoFe 2 O 4 distribution gradient and flexoelectric polarization induced by strain gradient under external magnetic field. This work presents a feasible way to modulate the magnetoelectric coupling in ferromagnetic-ferroelectric composite films for developing high-performance multiferroic materials at nanoscale.

Enhanced magnetoelectric response in 2-2 bilayer 0.50Pb(Ni1/3Nb2/3)O3–0.35PbTiO3–0.15PbZrO3/NiFe2O4thin films

“…Whereas in the present study and in our previous works [(1 − x)PNNZT-xCFO (x ⩽ 0.20)] [9] the linear trend in MD(%) as a function of the applied field is observed. Similar behavior has also been reported in CFO/Bi 5 Ti 3 FeO 15 bilayer composite heterostructural films [23], CFO/PZT particulate composite thin film [24] and other ferrite based systems [22,25,26]. However, in nanocrystalline ferrite thin films, high field susceptibility is observed to be significant in most cases.…”

Magnetoelectric coupling effect in lead-free Bi4Ti3O12/CoFe2O4composite films derived from chemistry solution deposition

“…With increasing dc bias magnetic field H bias , the α E values of BTO/CFO composite films increase quickly, reach maximum value of about 29.23 mV cm −1 Oe −1 when H bias is near 4.8 KOe, then gradually decreases. The magnetoelectric voltage coefficient α E for the present composite films is comparable with other composites films [43,44].…”

Anisotropy Magnetoelectric Coupling in NiFe2O4/Bi5Ti3FeO15 0‐3 Type Nanocomposite Films

“…have reported that magnetic particles were distributed in ferroelectric matrix, which can exterminate the substrate limitation. [9] We also have reported that the pseudo 1-3 structures in Bi 5 Ti 3 FeO 15 embedded with FeGa-micron size discs endows giant magnetoelectric effect. [10] Obviously, although the bismuthlayer-structure ferroelectrics (BLSF) has significant potential to become a new multiferroic material, which is still no abundant researches to carry out as a candidate for the nanocomposite films.…”

“…al. have reported that magnetic particles were distributed in ferroelectric matrix, which can exterminate the substrate limitation . We also have reported that the pseudo 1‐3 structures in Bi 5 Ti 3 FeO 15 embedded with FeGa‐micron size discs endows giant magnetoelectric effect .…”