X光吸收光譜(X-ray Absorption Spectroscopy,XAS)之X光吸收近邊緣結構(X-ray absorption near-edge structure,XANES)以及延伸X光吸收精細結構(Extended X-ray absorption fine structure,EXAFS)研究鈣鈦礦結構(perovskite-type)中A位置原子排列有序之Pr0.5Ba0.5MnO3電子結構與原子結構在不同磁相變點之特性。在此樣品中有兩種磁相轉變;居禮溫度位於311 K與尼爾溫度位於265 K。由X光吸收精細結構光譜發現於尼爾溫度時有很強的楊-泰勒形變,並且由X光吸收近邊緣結構中可見於此溫度時電子自旋方向較無序,相對於居禮溫度時楊-泰勒形變弱且電子自旋方向有序。經由此研究結果發現樣品中原子結構扭曲時電子不易於錳與氧間傳遞形成反鐵磁態。當扭曲不明顯時電子易於錳與氧間傳遞而形成鐵磁態。
In this study, we have investigated temperature-dependent magnetic properties of the half-doped perovskite-type manganese oxide Pr0.5Ba0.5MnO3 at different phase transitions using x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) spectroscopies. The Pr0.5Ba0.5MnO3 shows Curie (TC) and Néel (TN) temperature at 311 K and 265 K, respectively. The EXAFS spectra show strong and weak Jahn-Teller distortion at TN and TC respectively, while the XANES indicates the disordered and ordered spin direction severally. Via the research, the hopping energy increases and decreases at TN and Tc respectively due to strong or weak atomic distortion.