The change in polarization (i.e. the current) and

1. Noise Studies of Disordered Condensed Matter – Relaxor FerroelectricsM. B. Weissman, UIUC, DMR-0240644 Relaxor ferroelectrics are materials which freeze into a state with large electric polarization in small regions (“nanodomains”) but no long-range ordered polarization pattern. This combination allows them to have unusually huge piezoelectricity, i.e. coupling between electric fields and mechanical strain. They are already used for electro-mechanical transducers, but more applications are expected if the nature of the random-lookingfreezing can be better understood.One key question is whether some second type of order competes with ferroelectricity, as indicated by our previous experiments on noise and aging effects.. We find the field-induced conversion of the disordered to the ordered state proceeds via two very distinct steps, strongly supporting the idea that there is a well-defined glassy order competing with the ferroelectric order. The change in polarization (i.e. the current) and the changing components of the dielectric constantafter applying an electric field are shown for PbMg1/3Nb2/3O3, a standard relaxor. The differenttypes of changes in these different measurablesin the two steps show that different types of orderare involved in each.

2. Noise Studies of Disordered Condensed MatterM. B. Weissman, UIUC, DMR-0240644 Education: This grant supports work by a graduate student (Lambert Chao), an undergraduate (Kara Lamb) and a Visiting Research Professor (Eugene Colla). Recent graduates from this group have gone on to work for several hard-drive developers, as well as for other hardware developers, national labs, and universities. Recent graduates from this group have gone on to work for several hard-drive developers, as well as for other hardware developers, national labs, and universities. Outreach: The PI has prepared and edited hundreds of answers for a question-and-answer Web siterun by the Physics Department http://van.hep.uiuc.edu/van/qa/qaform.htm This site draws questions on all sorts of science topics from students of all ages from around the world. Here’s the PI’s favorite: http://van.hep.uiuc.edu/van/qa/section/stuff_about_space/the_earth_and_the_moon/20020821210810.htm. Here’s another, with more serious substance:http://van.hep.uiuc.edu/van/qa/section/states_of_matter_and_energy/boiling_evaporating_and_condensing/20030626151340.htm.