CeCrO_(3)的制备及磁、介电性能  

Preparation,magnetic and dielectric properties of CeCrO_(3)

作　　者：张亚乐 樊利国 王松伟[1,2] 张鑫[1,2] 崔梦范 杨瑞鑫 邓胜龙 周欣 ZHANG Yale;FAN Liguo;WANG Songwei;ZHANG Xin;CUI Mengfan;YANG Ruixin;DENG Shenglong;ZHOU Xin(School of Materials Science and Engineering,Guilin University of Electronic Technology,Guilin 541004,China;Guangxi Key Laboratory of Information Materials,Guilin University of Electronic Technology,Guilin 541004,China)

机构地区：[1]桂林电子科技大学材料科学与工程学院,广西桂林541004 [2]桂林电子科技大学广西电子信息材料构效关系重点实验室,广西桂林541004

出　　处：《桂林电子科技大学学报》2024年第5期498-504,共7页Journal of Guilin University of Electronic Technology

基　　金：国家自然科学基金(51802052);广西信息材料重点实验室基金(191004-Z,201021-Z,201020-Z,211014-Z)。

摘　　要：采用燃烧合成法制备CeCrO_(3)单相多晶样品,并利用X射线衍射仪、场发射扫描电子显微镜以及综合物性测量系统对样品进行结构、磁以及介电性能研究。直流磁化曲线显示,CeCrO_(3)样品在260K附近发生磁相变;高温顺磁段的磁化率倒数与温度具有线性关系,表明CeCrO_(3)遵循居里外斯定律;拟合得到的居里外斯温度为负值(-292.1K),表明样品内部存在反铁磁耦合特性。此外,该样品在120K附近发生磁化反转,源于Cr子晶格倾角反铁磁中的弱铁磁分量与顺磁性R子晶格因Cr反向内场极化形成的反向磁矩的相互作用。不同频率下介电常数随温度的变化关系显示,CeCrO_(3)在270K附近表现出热激活弛豫行为,源于麦克斯韦-瓦格纳效应。交流电导率研究表明,高频下的电导率出现色散现象,利用Jonscher方程对交流电导率进行拟合的结果表明,样品内载流子的传导可根据关联势垒跳跃(CBH)传导机制来理解。CeCrO_(3) single-phase polycrystalline samples were prepared by combustion synthesis technology.The structural,magnetic and dielectric properties of CeCrO_(3) were characterized by X-ray diffractometers,field emission scanning electron microscopes and physical property measurement systems.Magnetization measurements show that the magnetic phase transition of CeCrO_(3) sample occurs near 260 K.There is a linear relationship between the reciprocal of the magnetic susceptibility of the highly docile magnetic segment and the temperature,which indicates that CeCrO_(3) obeys Curie Weiss's law.The Curie-Weiss temperature is a negative value(−292.1 K),indicating the antiferromagnetic coupling between Cr sublattice moments.In addition,there exists magnetization reversal at 120 K,due to the interaction between weak ferromagnetic component in tilt antiferromagnetism of Cr sublattice and reverse magnetic moment of paramagnetic R sublattice due to reverse internal field polarization of Cr.The reciprocal of the dc magnetic susceptibility(1/x)varies linearly in a high temperature region,which follows the Curie-Weiss law.Magnetization reversals are attributed to the antiferromagnetic coupling between the R^(3+)moments and Cr^(3+)moments.The dielectric curves exhibit a thermal activation relaxation caused by Max,and the dispersion phenomenon was observed near 270 K.The Jonscher equation is used to fit the ac conductivity,the results show that the carrier conduction in the sample can be understood by the mechanism of correlated barrier hopping(CBH).

关 键 词：燃烧合成 反铁磁耦合 磁化反转 麦克斯韦-瓦格纳效应 关联势垒跳跃 

分 类 号：TB34[一般工业技术—材料科学与工程]