Collaborations with Beijing Institute of Technology

We have a highly successful partnership with Dr. Han Chun Wu, a former member of the APRG who is now based at the Beijing Institute of Technology. Much of the research focuses on thin magnetic films.

One of the main topics in this collaboration is the magnetic and transport properties of thin films. This research builds on the experience within the APRG of working with epitaxially deposited magnetic materials, particularly magnetite (Fe₃O₄), and their subsequent characterisation.

Some recent work includes the investigation of charge-orbital coupling in magnetite layers which are separated by an insulator layer. The influence of this ordering on the interlayer exchange coupling was studied.

Angular dependent transversal magneto-resistance (MR) measurements were carried out for epitaxial Fe₃O₄ and Fe₃O₄/NiO exchange biased systems. The results indicated an important role played by electron scattering at anti-phase boundaries (APBs).

We also looked at Mn₂Au/Fe bilayers. It was experimentally found that the Mn₂Au in these AFM/FM bilayer structures possessed a much lower critical temperature compared to bulk Mn₂Au, and this was bolstered by first-principle calculations.

ZnO is another material which has been investigated as part of this collaboration. The exciton spectra evolution of bent Zno wires was measured using high spatial/energy resolution cathodeluminescence spectroscopy at 5.5 K.

Schematic of a graphene stack sandwiched by two electrodes. Magnetoresistance properties of this device were reported in Advance Materials 24, 1862 (2012)

Selected Publications

Title:Strain induced exciton fine-structure splitting and shift in bent ZnO microwires
Authors:Zhi-Min Liao, Han-Chun Wu, Qiang Fu, Xuewen Fu, Xinli Zhu, Jun Xu, I.V. Shvets, Zhuhua Zhang, Wanlin Guo, Yamin Leprince-Wang, Qing Zhao, Xiaosong Wu & Da-Peng Yu
Source:Scientific Reports 2, 452 ( 2012)

Title:Large Magnetoresistance in Graphene Stack with Current Perpendicular to Plane Geometry
Authors:Zhi-Min Liao, Han-Chun Wu, S. Kumar, G. S. Duesberg, G.L.W. Cross, I. V. Shvets, and Da-Peng Yu
Source:Advanced Materials 24, 1862 (2012)

Title: Magnetization States of All-Oxide Spin Valves Controlled by Charge-orbital Ordering of Coupled Ferromagnets
Authors:Han-Chun Wu, Oleg N. Mryasov, Mohamed Abid, Kevin Radican, and Igor V. Shvets
Source:Scientific Reports 3, 1830 (2013)

Title: Mn₂Au: body centred tetragonal bimetallic antiferromagnet grown by molecular beam epitaxy
Authors:Han-Chun Wu, Zhi-Min Liao, R.G.S. Sofin, Gen Feng, Xiu-Mei Ma, Alexander B. Shick, Oleg N. Mryasov, and Igor V. Shvets
Source:Advanced Materials 24, 6374 (2012)

Title: Ultraviolet irradiation controlled memory effect in graphene field effect transistors
Authors:Jie Meng, Han-Chun Wu, Jing-Jing Chen, Ya-Qing Bie, Igor V. Shvets, Da-Peng Yu, and Zhi-Min Liao
Source:Small 9, 2240 (2013)

Title: Bias dependence of transverse magneto-resistance in epitaxial Fe₃O₄ and Fe₃O₄/NiO exchange biased system
Authors:Han-Chun Wu, R. Ramos, R. G. S. Sofin, Zhi-Min Liao, M. Abid, and I. V. Shvets
Source:Applied Physics Letters 101, 052402 (2012)

Title: Surface Plasmon on Topological Insulator Bi₂Te₃ Thin Flake/Dielectric Interface Enhanced ZnO Ultraviolet Photoluminescence
Authors:Zhi-Min Liao, Bing-Hong Han, Han-Chun Wu, L. V. Yashina, Yuan Yan, Yang-Bo Zhou, Ya-Qing Bie, S. I. Bozhko, K. Fleischer, I. V. Shvets, Qing Zhao, and Da-Peng Yu
Source:AIP Advances 2, 022105 (2012)