臺灣博碩士論文加值系統

本論文將討論具有鐵電磁性質的鈧鎦錳氧化合物(Sc1-xLuxMnO3)系統之三角型反鐵磁結構並將具有相似性質的釔鎦錳化合物(Y1-xLuxMnO3)做為比較。
有關鈧鎦錳氧化合物(Sc1-xLuxMnO3)系統的結構,磁性和錳的K吸收邊緣的X光光譜將做討論。所有樣本的吸收光譜轉折都落在接近6545電子伏特，顯示錳的價數皆為正三價。由於在MnO5 三角晶系d軌道和p軌道的混成減少，導致三角型的反鐵磁尼爾溫度從鈧錳氧的133 K減小到鎦錳氧的92 K。複雜的電子自旋方向的轉動在所有樣本中皆被觀察到。藉著相鄰錳的4p和3d軌道的微弱混成使1s軌道電子躍遷到3d軌道，使得的偶極躍遷K吸收邊緣的能量光譜分裂為鈧錳氧的2.27電子伏特和鎦錳氧的2.31電子伏特。較大的P1峰對應於躍遷到e'和e"軌道未填滿的電子自旋能階，而較小的P2峰則對應到躍遷到 e"軌道剩餘未填滿的電子自旋能階。

In this article, we studied on trianglar antiferromagnetic order in ferroelectromagnetic in the Sc1-xLuxMnO3 systems. We also studied on Y1-xLuxMnO3 systems as compared with Sc1-xLuxMnO3 systems.
Structural, magnetic and Mn K-edge X-ray absorption near-edge structure (XANES) spectroscopic studies for the stoichiometric, hexagonal Sc1-xLuxMnO3 (0 < x < 1) system are reported. The identical main threshold edge energy E0 of 6545 eV indicates trivalent Mn3+ for all samples. The triangular antiferromagnetic (AF) Neel temperature TN decreases monotonically from 133 K for ScMnO3 to 112 K for Sc0.5Lu0.5MnO3 and 92 K for LuMnO3, due to decreasing d-p hybridization in trigonal MnO5 block. Complex low temperature spin reorientations are observed for all samples. The K pre-edge features with energy separation E(P2 - P1) of 2.27eV for ScMnO3 and 2.31eV for LuMnO3 are from the 1s-3d dipole transition, which is weakly allowed through the hybridization of Mn 4p with 3d states of neighboring Mn atoms. The larger P1 peak is corresponding to transition into e'and e"minority spin states in MnO5 crystal field, and the smaller P2 peak is into leftover e"minority spin states.

Abstract (Chinese) I
Abstract (English) II
Contents III
List of Figures and Tables IV
Acknowledgments (Chinese) VII
Chapter 1 Introduction
Chapter 2 Experimental Details
2.1 Sample Preparation
2.2 Powder X-ray Diffraction Measurement
2.3 Magnetization and Magnetic Susceptibility Measurement
2.4 X-ray Absorption Spectra Measurement
Chapter 3 Results and Discussion
3.1 Structural analysis
3.2 Magnetic Properties
3.3 X-ray Absorption Near-Edge Spectra (XANES)
Chapter 4 Conclusion
References
Appendix

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