篇名 | 低溫高磁場 X 光吸收能譜 |
---|---|
卷期 | 228 |
並列篇名 | Low-temperature High-field X-ray Absorption Spectroscopies |
作者 | 秦伊瑩 |
頁次 | 051-062 |
出刊日期 | 202109 |
本文簡介以低溫高磁場X光吸收能譜來研究BaCoO₃及TbFe₃(BO₃)₄。前者的有效磁矩大於1.73μB,暗示非零的軌道磁矩,然而其晶體結構傾向磁量子數為零的基態;藉由X光磁圓偏振二向性實驗與理論模擬,我們發現Co之間的交互作用會造成能階的反轉,導致Co具有非零的軌道磁矩。後者在低溫會轉變為反鐵磁相,因Tb與Fe皆具有磁矩,我們利用X光線偏振二向性實驗確認其反鐵磁結構;此外,我們亦在不同磁場下進行實驗,以釐清其磁化量突然抬升背後的機制。
In this manuscript, the X-ray absorption spectroscopy studies on BaCoO₃ and TbFe₃(BO₃)₄ under high magnetic field are briefly introduced. For BaCoO₃, the effective magnetic moment (2.23 μ B) extracted from the magnetic susceptibility is larger than 1.73 μ B (the value without any orbital moment), while its crystal structure prefers the hole occupation of the a1g orbital with m = 0. Combining the X-ray magnetic circular dichroism and theoretical calculations, we found that the short distance between Co ions along the c axis makes the a1g orbital lower in energy and thus leads to the finite orbital moment. On the other hand, we employed X-ray linear dichroism to determine the antiferromagnetic structure of TbFe₃(BO₃)₄ and performed experiments under various magnetic field to investigate the significant enhancement of the magnetization in the antiferromagnetic phase.