X-ray absorption spectroscopy studies of spin-orbit coupling in 5d transition metal oxides.
In order to examine the effects of strong valence band spin-orbit coupling (SOC) in 5d transition metal oxides (TMOs), we have investigated the L(2) and L(3) edge white-line intensities of the x-ray absorption spectra of several 5d TMOs. The white-line intensities at both edges are found to decrease monotonously with increasing 5d electron occupancy, while their ratio showed anomalous behavior for late 5d TMOs (IrO(2), PtO(2), and Au(2)O(3)), deviating significantly from the theoretical value of 2 expected for the case of weak SOC. This observation serves as a clear experimental indication of strong SOC effects in 5d TMOs. We also discussed how the 5d TMOs can have charge transfer effects different from their counterpart 5d elemental metals by making comparative studies. Our works demonstrate the importance of j quantum states due to strong SOC in the 5d system.
CSCMR and FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of Korea. zax@snu.ac.kr
Deok-Yong
DY
Cho
Junghwan
J
Park
Jaejun
J
Yu
Je-Geun
JG
Park
D000042:Absorption; D000465:Algorithms; D002627:Chemistry, Physical / Q000379:methods*; D003460:Crystallization; D004583:Electrons; D006046:Gold / Q000737:chemistry; D007495:Iridium / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D008962:Models, Theoretical; D010087:Oxides / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry; D011208:Powders / Q000737:chemistry; D056928:X-Ray Absorption Spectroscopy / Q000379:methods; D014965:X-Rays
D008670:Metals; D010087:Oxides; D011208:Powders; C514637:platinum oxide; C044458:iridium oxide; D007495:Iridium; D010984:Platinum; D006046:Gold