Direct observation of charge re-distribution in a MgB2 superconductor

作者：Wu Sheng Yun^*; Shih Po Hsun; Ji Jhong Yi; Chan Ting Shan; Yang Chun Chuen

来源：Superconductor Science and Technology, 2016, 29(4): 045001.

DOI：10.1088/0953-2048/29/4/045001

• negative thermal expansion
• superconductivity
• two-phonon effect

To study the origin of negative thermal expansion effects near the superconducting transition temperature T-C in MgB2, low-temperature high-energy synchrotron radiation x-ray diffraction was used to probe the charge redistribution near the boron atoms. Our results reveal that the in-plane hole-distribution of B- hops through the direct orbital overlap of Mg2+ along the c-axis at 50 K and is re-distributed out-of-plane. This study shows that the out-of-plane pi-hole distribution plays a dominant role in the possible origin of superconductivity and negative thermal effects in MgB2.

• 出版日期2016-4
• 单位东华大学