Functional rare earth ion defects and the related phenomena
일 시 : 2021년 10월 27일 수요일 16:30
연 사 : 이 윤 상 교수 (숭실대학교 물리학과)
장 소 : 온라인 진행 (https://us02web.zoom.us/j/83511628746)
HOST : 문 순 재 교수님
초 록
In strongly correlated electronic systems, e.g., transition metal oxides (TMOs), functional ionic defects, mainly, oxygen vacancies, have been found to play a crucial role in determining the electronic properties of TMOs and improving their functionalities by introducing charge carriers, lattice distortion, and ionic dynamics. As another functional ionic defects, we consider the doping of rare earth (RE) ions with 4f orbitals. Due the f-f transitions allowed in the visible region, the RE ions have been commonly used for applications as phosphors, lasers, and amplifiers. Since the f–f transitions are parity-forbidden, the non-inversion symmetrical character of the crystal field at the RE ions should be essential in allowing the forced electric dipole transitions. In this sense, the emission profiles of the RE ions should be strongly affected by the local structural symmetry and could be employed in probing the local lattice distortion. In this talk, I introduce several studies on the structural properties of some electronic oxides by using the emission spectroscopy on the RE ions doped to them.