(La0.57Dy0.1)Sr0.33MnO3多晶纳米颗粒的磁热性能

采用非晶态前驱体的方法在800 ℃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(358 K) (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5 T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.

Magnetocaloric Properties in (La0.57Dy0.1)Sr0.33MnO3 Poly- crystalline Nanoparticles

Nanosized particles of (La0.57Dy0.1)Sr0.33MnO3 perovskite-type oxides were successfully synthesized at relatively low calcinated temperature of 800 °C for 10 h using amorphous molecular alloy as precursor. X-ray diffraction (XRD) and electron diffraction (ED) revealed that the resulting product is of pure single-phase rhombohedral structure. From the measurements and calculation of isothermal magnetization at different temperatures, we discovered that the maximum magnetic entropy change at TC (358 K) increases near linearly with magnetic field increasing and shows no sign of saturation even under 5 T; moreover, a comparatively large magnetic entropy change with broader peak temperature range around the Curie temperature is also observed, and this good performance may be related to the large surface and interface of nanoparticles.