Session B20: Focus Session: Properties of Ferroelectrics and Relaxors
11:15 AM–2:15 PM, Monday, March 5, 2007
Colorado Convention Center Room: 105
Sponsoring Unit:
DMP
Chair: Hans Christen, Oak Ridge National Laboratory
Abstract ID: BAPS.2007.MAR.B20.8
Abstract: B20.00008 : Cubic ground state of field-cooled PbMg$_{1/3}$Nb$_{2/3}$O$_3$
1:03 PM–1:15 PM
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Abstract 
Authors:
Peter Gehring
(National Institute of Standards and Technology)
Chris Stock
(Johns Hopkins University)
Guangyong Xu
(Brookhaven National Laboratory)
Haosu Luo
(Chinese Academy of Sciences)
Hu Cao
(Virginia Tech)
Jiefang Li
(Virginia Tech)
Dwight Viehland
(Virginia Tech)
Gen Shirane
(Brookhaven National Laboratory)
Neutron and x-ray diffraction techniques have been used to study the competing long and short-range polar order in the relaxor PbMg$_{1/3}$Nb$_{2/3}$O$_3$ (PMN) under the influence of an external [111]-oriented electric field. While the bulk unit cell remains cubic for electric fields up to 8\,kV/cm, a suppression of the diffuse scattering and a concomitant enhancement of the Bragg peak intensity is observed below $T_c=210$\,K, indicating a more ordered structure with increasing electric field yet an absence of a long-range ferroelectric ground state. The electric field strength has little effect on the diffuse scattering above $T_c$. The absence of hysteresis suggests that the ground state of PMN may not be a frozen glassy phase, but may be better understood in terms of random fields introduced through the presence of structural disorder.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.MAR.B20.8