Ce-doping effect on modulation of spin-exchange interaction and dielectric behaviour of nanostructured LaFeO3 orthoferrites
Ce-doping effect on modulation of spin-exchange interaction and dielectric behaviour of nanostructured LaFeO3 orthoferrites
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DOI：
10.1016/j.matchemphys.2019.122457
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发表时间：
2020-02
影响因子：
4.6
通讯作者：
Javed R. Sheikh;S. Acharya;U. Deshpande
中科院分区：
文献类型：
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作者：
Javed R. Sheikh;S. Acharya;U. Deshpande
本文尝试将Ce掺杂的LaFeO_3(LCFO)系统作为单相室温多铁体(MFS)来研究。采用微波辅助凝胶燃烧法制备了不同组成的Ce[La_(1-x)CexFeO_3(0，≤_x，≤_(0.1))]纳米晶LCFO。对X-射线衍射数据的Rietveld分析表明，当x=0.10时，体系保留了空间群为PbMn的扭曲正交相；而当x=0.1时，检测到与CeO2有关的杂质相，表明Ce在LiFO中的固溶度极限为x-≤=0.08。在傅里叶变换红外光谱中发现了与Ce平移振动有关的新的声子模，在300cmLFO 1以上有几个拐点，这是Ce对−进行结构修饰的明显标志。Ce掺杂的增强磁化强度归因于Ce3+-O-Fe3+和Fe3+-O-Fe3+的自旋交换作用。M-H曲线表现出部分铁磁性，LCFO具有G型反平行自旋排列。温度驱动的介电和磁行为表现出在奈尔温度附近的转变，这是LCFO系统中磁电耦合的证据。Ce掺杂显著提高了LFO的磁化强度、矫顽力和剩余磁化强度，降低了LFO的介电常数、损耗和漏电流，表明LCFO铁氧体是一种很有前途的室温复铁体材料。
In present attempt, Ce-doped LaFeO3(LCFO) system is explored as single phase room temperature multiferroics (MFs). Nano-crystalline LCFO system with various compositions of Ce [La1-xCexFeO3(0 ≤ x ≤ 0.1)] are synthesized by microwave-assisted gel combustion method. Detailed Rietveld analysis of X-ray diffraction data revealed that the systems retain distorted orthorhombic phase with space group Pbmn for x < 0.10; However, impurity phase related to CeO2is detected for x = 0.1 indicates solid solubility limit of Ce in LFO is x ≤ 0.08. New phonon mode related to Ce translational vibration with several kinks above 300 cm−1are detected in Fourier transform infrared spectra; is a clear indication of structural modification of LFO by Ce. Enhanced magnetization with Ce doping content are attributed to spin exchange interaction Ce3+-O-Fe3+and Fe3+-O-Fe3+. M-H curves exhibit partial ferromagnetic nature with G-type antiparallel spin arrangement of LCFO. Temperature driven dielectric and magnetic behaviour exhibit transition near Néel temperature evidence for magneto-dielectric coupling in LCFO systems. Remarkable enhancement in the magnetization, coercivity, and remanant magnetization with reduction in dielectric constant, loss and leakage current of LFO by Ce-doping suggests that LCFO ferrites are promising materials as room temperature multiferroic.