銪釔錳氧化物奈米棒之結構與磁性交互作用研究

Interplay between structure and magnetic properties of Y1-xEuxMn2O5 nanorods

謝孟辰(Meng-Chen Hsieh)

指導教授 ： 楊仲準

中原大學/理學院/物理研究所/碩士(2015年)

https://doi.org/10.6840/cycu201500813

摘要

以水熱合成法製備出Y1-xEuxMn2O5(x = 0.2、0.4、0.5、0.6、0.8)之奈米棒磁性材料，將Y0.5Eu0.5Mn2O5樣品再經由熱退火溫度400、500、600、700、800、900和1000℃後得到不同尺寸大小熱退火溫度之樣品。以X光繞射實驗鑑定出所有樣品結構皆是斜方晶系Pbam純相。用高解析度TEM與高解析度SEM影像搭配選區電子繞射分析與統計，可知樣品表面形貌與尺寸大小，以短軸×長軸之標示依序為38(20) nm×81(42) nm、63(10) nm×119(22) nm、49(15) nm×100(43) nm、66(19) nm×138(39) nm、58(16) nm×136(48) nm、54(20) nm×97(41) nm、94(15) nm×167(45) nm、120(33) nm×201(74) nm。樣品之長軸方向皆沿著晶軸c軸方向成長，定義為長軸方向來辨別不同樣品。
磁化率實驗量測中，各尺寸樣品在低溫2K磁滯曲線量測時，只有 = 201 nm之樣品達到飽和呈完整的磁滯曲線。ZFC推算有效磁矩μeff，實驗值為8.15μB與8.22μB，大於軌道角動量猝滅的理論值6.28μB，顯示參雜效應會使軌道角動量猝滅效應消失。
變溫變磁場拉曼量測 = 80、97與201 nm三個樣品，未外加磁場(0T)時，各溫度拉曼峰值有不規則扭曲，在外加磁場(0.2T)下時，Ag與B1g模會受到磁場影響，顯示它具有磁滯伸縮或磁聲交互作用產生。

關鍵字

多鐵材料 ； 磁性 ； 銪釔錳氧化物

並列摘要

Using hydrothermal synthesis method to prepare Y1-xEuxMn2O5(x = 0.2、0.4、0.5、0.6、0.8) of magnetic nanorods material. And then let the sample Y0.5Eu0.5Mn2O5 go through the different thermal annealing temperatures, after that we can obtain the samples of different sizes of thermal annealing temperatures. In X-ray diffraction experiments identify the structure of all the samples are Pbam pure orthorhombic phase. With high-resolution TEM and SEM images to match the high resolution SAED’s analysis and statistical, shows that the sample surface morphology and size. To indicate the short axis × long axis sequentially, is 38(20) nm×81 (42) nm, 63(10) nm×119(22) nm, 49(15) nm×100(43) nm, 66(19) nm×138(39) nm, 58(16) nm×136(48) nm, 54(20) nm×97(41) nm, 94(15) nm×167(45) nm, 120(33) nm×201(74) nm. All the long axis of nanorods are parallel to c axis of the crystal. We can define long axis direction to identify the different samples.
Susceptibility measurements for each sample, only = 201 nm of the sample is complete saturated at low 2K hysteresis curve. ZFC calculate the effective magnetic moment μeff, the experimental value 8.15 μB and 8.22 μB, greater than the theoretical value 6.28 μB. Shows that the doping effect will let quenching of the orbital angular momentum vanish .
Variable temperature magnetic field Raman measurements = 80, 97 and 201 nm samples, without applied magnetic field (0T), the respective temperature Raman peak have irregular distortions. In magnetic field (0.2T), Ag model and B1g model will influence by the magnetic field. Shows that it has magneto-restriction or magnetic-phonon interaction.

並列關鍵字

magnetic ； multiferroic ； RMn2O5

參考文獻

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