| 报告题目 | Interplay of spin, orbital and lattice correlations in an XY-like spin-glass (Ni0.4Mn0.6)TiO3 single-crystal: Neutron and X-ray studies |
| 报告人 | 彭维锋 教授 |
| 报告人单位 | 台湾淡江大学物理系 |
| 报告时间 | 2018-09-04 |
| 报告地点 | 合肥微尺度物质科学国家研究中心九楼会议室（9004） |
| 主办单位 | 合肥微尺度物质科学国家研究中心、中国科学技术大学物理系、中国科学院强耦合量子材料物理重点实验室 |
| 报告介绍 | 报告摘要：
Small angle neutron scattering (SANS), resonant inelastic X-ray scattering (RIXS) and X-ray absorption spectroscopy have been carried out to study the correlations of magnetic properties and electronic/atomic structures in an XY-like spin-glass (SG) state of Ni0.4Mn0.6TiO3 (NMTO) single crystal. SANS presents the texture of toroidal glass and H (magentic)-T (temperature) phase diagram in NMTO. The results of RIXS show the evidence of crystal field (d-d) excitations at Ni and Mn L3-edge. Importantly, the spin-flip excitation is observable which is prominent at Ni L3-edge RIXS spectra in NMTO mainly. Using temperature-dependent X-ray linear dichroism (XLD) and extended X-ray absorption fine structure (EXAFS) measurements, it has revealed that phonon softening/symmetry breaking occurred at low temperature near SG phase transition due to the local static disorder in Ni-O bond length, and further induced the Ni 3d electron preference occupation charge from in-plane (3dx2-y2) to out-of-plane (3dz2-r2) states, demonstrating the strong correlations of spin, orbital and lattice in an XY-like SG state of NMTO.
报告人简介： 彭维锋教授1980年毕业于台湾国立中央大学物理系，1990年获University of Notre Dame 物理学博士学位，随后入职淡江大学物理系任副教授，1997年始任教授至今。曾于2001-2004任台湾物理学会理事长，现为台湾科技部自然科学司国际合作处咨询专家负责人，并领导淡江大学的软X射线谱学研究团队及透射扫描X射线谱学研究团队。他的专业特长是利用先进光源手段开展凝聚态物理的研究。他的专业活动也包括促进基于台湾光源的国内外合作研究。 |
