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采用非晶态前驱体的方法在800°C的低温下制备出(La0.57Dy0.1)Sr0.33MnO3纳米颗粒,用XRD、HRTEM和MPMS等手段对纳米颗粒的微观结构和磁性能进行研究。XRD和ED分析表明,所有的样品都具有单相钙钛矿结构;通过对样品不同温度下等温磁场的测量和计算,发现在居里温度点(358K)(La0.57Dy0.1)Sr0.33MnO3纳米颗粒的最大磁熵变随着磁场的增加而增加,即使在5T磁场下也没有达到饱和;居里温度附近纳米颗粒具有较大的磁热效应和较宽的峰值温度范围,这些良好性能可能和纳米颗粒具有大的表面和界面有关。
(La0.57Dy0.1) Sr0.33MnO3nanoparticles were prepared by using amorphous precursors at 800 ℃. The microstructure and magnetic properties of the nanoparticles were investigated by XRD, HRTEM and MPMS. XRD and ED analysis showed that all the samples had a single-phase perovskite structure. By measuring and calculating the isothermal magnetic field at different temperatures, it was found that at the Curie temperature (358K) (La0.57Dy0.1) Sr0.33MnO3 The maximum magnetic entropy change of nanoparticles increases with the increase of magnetic field and does not reach saturation even under 5T magnetic field. The nanoparticles near Curie temperature have larger magnetocaloric effect and wider peak temperature range, and these good properties may Nanoparticles have large surfaces and interfaces.