| Summary: | 碩士 === 中原大學 === 物理研究所 === 103 === 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 <LC> long axis direction to identify the different samples.
Susceptibility measurements for each sample, only <LC> = 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 <LC> = 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.
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