Dr. Zhihai Zhu
Massachusetts Institute of Technology (MIT), USA
Dr. Zhu obtained his Ph. D. in 2016 from the University of Connecticut in the USA, under the advice of Prof. Barrett O. Wells. He currently is a postdoctoral associate at Massachusetts Institute of Technology (MIT) under the direction of Prof. Riccardo Comin. Dr. Zhu’s research lies in correlated-electron physics in transition metal oxides (TMOs). His study is materials and problem based, tackling the full spectrum of a problem from material synthesis (PLD, OMBE) to advanced measurements (Neutron scattering, muon spin rotation, resonant elastic/inelastic x-ray scattering etc.), often at large scale facilities at national labs.
2019-06-12 - 2019-06-15 Office No:
Inviter: Chen Fang
Contact Person: Liu Yang Contact Number: 9907
|Talk Title: Resonant Elastic X-ray Scattering Study of Transition Metal Oxides
Talk Place: M253
Talk Time: 13-Jun-2019 10:00 am
Resonant elastic X-ray scattering (REXS) is a powerful tool to study orderings of spin, charge, and orbital degrees of freedom. I will present our studies on RuO2 and α-Sr2CrO4, by using the REXS technique. (1) Ruthenium oxide (RuO2) has been considered as a Pauli paramagnet. We studied the magnetic ordering of thin films and bulk crystals of rutile RuO2 using resonant magnetic X-ray scattering (RXS) across the Ru-L2 absorption edge and have established the presence and texture of the collinear antiferromagnetic order in RuO2 with TNéel > 300 K. (2) We investigate the electronic ground states of Sr2CrO4, a compound that is a rare embodiment of the spin-1 Kugel-Khomskii model on the square lattice. We have used resonant X-ray diffraction at the Cr-K edge to reveal Néel magnetic order below TN = 112 K, as well as an additional electronic order at the “stripe” wavevector QS = (ℼ; 0) below Ts < 50 K. These findings are examined within the framework of the Kugel-Khomskii model in the mean-field approximation, which supports the stability of the spin Néel phase with subsequent lower-temperature stripe orbital ordering.