Department of Chemistry
Travel Report: Zihe Ren, Chemistry
Zihe Ren, a Doctoral student in Chemistry, received a Graduate International Research Travel Award to further his research in the UK. His report:
My trip started in Krakow, Poland where I attended the 13th international meeting in Ferroelectrics (IMF-13) Sept.01-06, 2013. In that conference I presented my research entitled: “Study of PbZrO3-Pb(Mn1/2W1/2)O3 Antiferroelectric Ceramic”.
The research started right after the conference. I went to University of Warwick (Coventry, UK) where Dr. A.M. Glazer (professor retired from University of Oxford) and his wife, Dr. Pam A. Thomas work.
Our collaboration include three projects: 1). Study of the phase transition in Pb-based (Pb(In1/2Nb1/2)O3 – Pb(Mg1/3Nb2/3)O3 – PbTiO3) complex ferroelectric perovskite crystal by high resolution, high temperature X-ray diffraction method. 2). Determination of the ferroelectric phase existed in an antiferroelectric material (PbZrO3-Pb(Mn1/2W1/2)O3) by diffraction and second harmonic generation method. 3). Assisting Dr. Nan Zhang in her research on PZT single crystal at Rutherford Appleton Laboratory (RAL), Chilton, Oxfordshire, UK. All three projects have remarkable results.
In project 1, we have already determined the phase transition being ferroelectric rhombohedral to a low symmetry ferroelectric phase by polarized light microcopy and dielectric spectroscopy in the 4D labs, SFU. However, our X-ray facility was not able to conduct high resolution, high temperature structural analysis. Therefore, my samples were taken to University of Warwick to be examined in their diffractometers (Panalytical X'Pert Pro MRDs with a Cu Kα1 hybrid monochromator). The refinement of the diffraction patterns shows clear rhombohedral (R3m)à Monoclinic (Cm) phase transition.
In project 2, the existence of ferroelectric phase has been verified in SFU by dielectric spectroscopy and pyroelectric analysis. However, due to the same reason as for project 1, our X-ray facility was not good enough to find out the detailed symmetry for this ferroelectric phase. With the help of Dr. David Walker, Dr. David Woodward, Dr. A.M Glazer and Dr. Pam A. Thomas, the ferroelectric phase was determined as rhombohedral with R3m space group.
In project 3, Dr. Zhang and I conducted series of neutron diffraction experiments on our PZT single crystal (grown in 4D lab, SFU) in station SXD, at Rutherford Appleton Laboratory (RAL). The diffraction result was considered as the highest quality in the world, revealing the mixture of symmetries in so called “morphotropic phase boundary region (MPB)”. As a result, the software has to be rewritten in order to analyze such complex structure.
Currently, one manuscript for project 1, two manuscripts for project 2 are under revision. With the work done in UK, both projects are now completed.
Physics department, Univeristy of Warwick
Zihe Ren in University of Warwick
Dr. David Walker testing the X-ray diffractometer
Zihe Ren within the RAL facility
The PZT single crystal sample ready for neutron diffraction experiment
Large size fish and chips in London!