Layered Perovskite NLaFe 0.5 Co 0.5 O 3 -Bi 4 Ti 3 O12 Multi-iron Properties Of The Film And Its Loop Dynamics

In order to synthesize single-phase room-temperature multiferroic nLaFe_0.5Co_0.5O₃-Bi₄Ti₃O₁₂?nLFC-BTO?materials,this paper conceives inserting the antiferromagnetic nLaFe_0.5Co_0.5O₃?LFC??n=0.5,1?unit into the ferroelectric Bi₄Ti₃O₁₂?BTO?matrix of layered perovskite.Single-phase multiferroic nLFC-BTO thin films were successfully prepared on?111?Pt/Ti/SiO₂/Si?100?via a sol-gel process,and ferroelectricity,dielectricity,magnetism,and magneto-dielectric effect of thin films were studied.To obtain some information about ferroelectric domain structure and polarization reverse,the dynamic hysteresis scaling for thin films are further discussed.The main results and conclusions are as follows:1.nLFC-BTO thin films were deposited on Pt/Ti/SiO₂/Si substrates through a sol-gel process.The films have a single-phase layered Aurivillius structure of the space group Fmm2,indicating that the antiferromagnetic LFC unit is successfully inserted into the ferroelectric BTO matrix of the three-layered perovskite.2.The 0.5LFC-BTO and LFC-BTO films all present obvious ferroelectric and magnetic properties at room temperature.A remanent polarization 2P_r and a saturated magnetization M_s of 0.5LFC-BTO films are ⁴8 mC/cm² and ².0 emu/cm³,respectively;The 2P_r and M_s values of LFC-BTO films are ⁴2 mC/cm² and ⁷.2 emu/cm³,respectively.More importantly,the room-temperature magneto-dielectric effect were all observed in the 0.5LFC-BTO and LFC-BTO films,probably resulting from spin reorientation under applied magnetic fields by affecting the interaction between the local dipoles of Fe²⁺ and Fe³⁺.Under the magnetic field of 0.5 T,the magneto-dielectric coefficient?MDC?of 0.5LFC-BTO and LFC-BTO films are ⁰.75% and ³.8%,respectively.3.Two kinds of dielectric anomaly peaks all appear from dielectric spectrums of the 0.5LFC-BTO and LFC-BTO films.Two kinds of dielectric anomaly peaks indicate two types of dielectric relaxation behaviors.This study provides support for the coexistence of Fe²⁺ and Fe³⁺ and existence of oxygen vacancy in the films.4.In high-E₀ and high-f,the scaling power-law of 0.5LFC-BTO and LFC-BTO films can be expressed by <A> ? f^-0.071E₀^1.856 and <A> ? f^-0.197E₀^1.751,respectively.The absolute value of exponent a and b for two kinds of thin films is lower than that of other ferroelectric films.This indicates that 0.5LFC-BTO and LFC-BTO films have all the strong ability of the domain reversal and good frequency stability.In short,the nLFC-BTO films are appropriate for developing ferroelectric random-access memory.