煅烧温度对La_(0.6)Sr_(0.4)MnO_3晶体结构及电磁性能的影响

采用传统固相反应法在不同烧结温度下制备了La_(0.6)Sr_(0.4)MnO_3样品,通过X射线衍射仪(XRD)和扫描电镜显微镜(SEM)对样品进行了物相结构和微观组织分析,比较了不同烧结温度下样品的烧结性、介电性和铁磁性能。研究结果表明,当烧结温度从1100℃增加到1200℃时,La_(0.6)Sr_(0.4)MnO_3样品的介电损耗呈降低趋势,介电常数数值呈增加趋势,并在测量频率范围内显示负值。随着烧结温度的增加,La_(0.6)Sr_(0.4)MnO_3样品的铁磁性呈现先上升后下降的趋势。当烧结温度为1150℃时,其饱和磁化强度达到最大,为37.80A·m~2·kg~(-1)。说明可以通过改变煅烧温度来有效调节晶粒尺寸,从而改进La_(0.6)Sr_(0.4)MnO_3样品的介电性能和铁磁性能。

Influence of Calcination Temperature on Crystal Structure and Electromagnetic Properties of La0.6Sr0.4MnO3

La0.6Sr0.4MnO3 samples were successfully synthesized by the traditional solid state reaction technology at the different calcination temperature.Phase constitution and microstructure of the prepared samples were analyzed by X-ray Diffraction (XRD) and scanning electron microscope (SEM).The sinterability,dielectric property and ferromagnetic properties were also studied for samples sintered at the different temperature.The results showed that dielectric loss and permittivity of La0.6Sr0.4MnO3 samples have a tendency of show descending and ascending trend respectively at with the calcination temperature ranges increasing from 1100℃ to 1200℃.Within the scope of frequency measured,it also exhibited negative permittivity.In addition,it is found that the ferromagnetic property of La0.6Sr0.4MnO3 first increases and then decreases with the calcination temperature increased.When the calcination temperature is 1150℃,its the Ms reaches the maximum with of 37.80A·m2·kg-1.It indicates that calcination temperature can change grain size to effectively regulate tune dielectric property and ferromagnetic feature by changing grain size of La0.6Sr0.4MnO3 samples.