双层稀土锰氧化物La_(2-2x)Sr_(1+2x)Mn_2O_7的ESR研究  

Electron Spin Resonance(ESR) of Bilayered Manganite La_(2-2x)Sr_(1+2x)Mn_2O_7

作　　者：樊宝元[1] 郑丽萍[1] 赵建军[1] 

机构地区：[1]包头师范学院物理科学与技术学院,内蒙古包头014030

出　　处：《阴山学刊（自然科学版）》2011年第1期20-22,共3页Yinshan Academic Journal(Natural Science Edition)

基　　金：内蒙自然科学基金资助项目(项目编号:2009MS0101)

摘　　要：电子自旋共振(简称ESR)是一种研究磁性关联的很有效的的实验手段。通过测量样品的变温ESR谱线,分析谱线参数随温度的变化关系,能够获得很多关于静态和动态磁耦合的信息。本文采用光学浮区炉制备锰氧化物La2-2xSr+2xMn2O7(x=0.38)单晶样品,利用电子自旋共振研究层状锰氧化物单晶的MnO2双层间(interlayer)的耦合能。谱线中出现了代表层间反铁磁关联的高场光学模和低场声学模。通过分析声学模与光学模的共振场与积分强度随温度的变化,发现这些层间的反铁磁随着温度的变化逐渐发展,这表明利用铁磁共振方法能够研究层状锰氧化物La2-2xSr+2xMn2O7的层间耦合,研究结果为这个体系内磁性关联的研究提供了一种新的方法。Electron spin resonance(ESR) has proved to be a powerful tool in the study of both static and dynamic magnetic correlation in manganites.Valuable information can be obtained regarding the interplay of different interactions in the system through a study of the temperature dependence of various ESR parameters.In this thesis,single crystals of La2-2xSr1+2xMn2O7(x=0.38) were melt-grown in flowing air in a floating-zone optical image furnace,the interlayer coupling of bilayered manganite single crystal has been studied by ESR.A high-field optical mode in addition to the acoustic mode was observed.Analysis of the resonance field and intensity for both modes reveals the evolution of the interlayer coupling as a function of temperature.Our study suggests that ferromagnetic resonance provides a useful method to investigate the interlayer coupling in bilayered manganites opens a new perspective on studying such mixed FM-AFM systems.

关 键 词：磁性关联 电子自旋共振 层状锰氧化物 层间耦合 

分 类 号：C55[社会学]