Multiferroic Properties and Magnetoelectric Coupling of Fe‐Doped (Ba_0.7Ca_0.3)TiO₃‐Ba(Zr_0.2Ti_0.8)O₃ Ceramics

Abstract

Fe-doped (Ba 0.7 Ca 0.3 )TiO 3 -Ba(Zr 0.2 Ti 0.8 )O 3 (BCZT) ceramics are prepared by a conventional solid-state reaction method, and their structure, multiferroic, and coupling properties are investigated. Ferromagnetism and magnetoelectric coupling are successfully realized by Fe 3þ doping. Meanwhile, Fe 3þ doping in BCZT results in a gradual transition from typical ferroelectrics to relaxor ferroelectrics or even quantum paraelectrics. In consequence, obvious magnetodielectric (MD) effect is observed only among the morphotropic phase boundary (MPB) temperature range. For (Ba 1.7 Ca 0.3 )(Zr 0.2 Ti 1.7 Fe 0.1 )O 6 ceramics, the coexistence of ferroelectricity and ferromagnetism along with a large MD effect is obtained below 200 K. Herein, the results highlight the role of MPB on the magnetoelectric coupling of ferroelectrics with a percolating of magnetic ions.

Dielectric Properties in Transition Metal and Rare‐Earth‐Doped Multiferroic BaTiO3 Nanoparticles

“…Moreover, the peak is broadened with increase in x , which is typical for a relaxor ferroelectric. The phase transition disappears for large Fe dopant concentration (curves 4 and 4a) in good agreement with the experimental data of Gong et al ( x = 0–0.4). BaFeO 3 is a pure magnetic material, and it shows no ferroelectric properties, P = 0.…”

“…Temperature dependence of the real part of the DC for BTO (bulk, curves 1-4; and NP with N ¼ 5 shells, curves 1a-4a) for different Fe-doping content x: x ¼ 0 (curves 1 and 1a); x ¼ 0.1 (curves 2 and 2a); x ¼ 0.4 (curves 3 and 3a); x ¼ 0.6 (curves 4 and 4a). concentration (curves 4 and 4a) in good agreement with the experimental data of Gong et al [18] (x ¼ 0-0.4). BaFeO 3 is a pure magnetic material, and it shows no ferroelectric properties, P ¼ 0.…”

Thermally-stable high energy storage performances and large electrocaloric effect over a broad temperature span in lead-free BCZT ceramic

“…This lead-free ceramic possesses a broad frequency-dependent peak corresponding to the temperature-dependent dielectric susceptibility, lower remnant polarization, and slimmer hysteresis loops due to the relaxor ferroelectric nanodomains, which are essential for realizing extremely high energy densities and efficiencies. [14][15][16][17] Moreover, it was reported that BCZT ceramics possess low dielectric loss (tan d) (1-3%), which is encouraging for obtaining high-efficiency energy storage density. 10,[18][19][20][21] BCZT relaxor ferroelectric ceramics have been attracting much attention for energy storage applications and electrocaloric cooling devices owing to their outstanding dielectric and ferroelectric properties.…”

Enhanced recoverable energy storage density and efficiency in (1 − x)Ba0.85Ca0.15Zr0.1Ti0.9O3-xSrTiO3-MnO2 lead-free ceramics

“…S3(a)-(c) of the ESI, † respectively show the SEM morphology of BCZT ceramics sintered at 1200 1C, 0.4BCZT-0.6ST ceramics sintered at 1200 1C, and 0.4BCZT-0.6ST ceramics sintered with the two-step sintering method, where 3 mol% MnO 2 is added as a sintering aid. Compared with the pure BCZT ceramics without sintering aid, 30 the addition of MnO 2 decreases the average grain size from 8 mm to 3.37 mm (Fig. S3(d method is adopted for the (1 À x)BCZT-xST (x Z 0.6) ceramics and a dense and fine grain morphology is obtained (Fig.…”

“…A uniform and dense microstructure without porosity is observed for all the ceramics.Fig.S3(a)-(c) of the ESI, † respectively show the SEM morphology of BCZT ceramics sintered at 1200 1C, 0.4BCZT-0.6ST ceramics sintered at 1200 1C, and 0.4BCZT-0.6ST ceramics sintered with the two-step sintering method, where 3 mol% MnO 2 is added as a sintering aid. Compared with the pure BCZT ceramics without sintering aid,30 the addition of MnO 2 decreases the average grain size from 8 mm to 3.37 mm (Fig.S3(d), ESI †) and lowers the sintering temperature from 1450 1C to 1200 1C, indicating the effect of the sintering aid MnO 2 on the nucleation and growth of BCZT as well as the grain refinement. Moreover, the introduction of ST further reduces the grain size to about 0.47 mm (Fig.…”