Probing Local Origins of Nonlinearity in Ferroelectric Films

1. Probing Local Origins of Nonlinearity in Ferroelectric Films Susan E. Trolier-McKinstry, Pennsylvania State Univ University Park, DMR1005771 Engineered grain boundary Ferroelectric materials (materials that have a switchable spontaneous polarization) are at the heart of ultrasonic imaging systems for fetal and cardiac monitoring, the multilayer capacitors used in virtually every handheld device and computer, as well as in high precision positioning systems for advanced microscope systems. There are a number of unanswered questions surrounding the properties of the materials under high alternating electric fields; these are becoming increasingly more important as devices are continuously miniaturized. This program is addressing open questions associated with the field dependence of the properties by investigating the role that defects play in influencing the mobility of ferroelectric domain walls. Here, the influence of one grain boundary on the functional response of the material can be seen; on average, the grain boundary suppresses the response. Topology Functional Response

2. Bonding, Structure, and Structure-Property RelationsSusan E. Trolier-McKinstry, Pennsylvania State Univ University Park, DMR 1005771DMR - 1005771 180 high school students built models of the crystal structures of salt, diamond, and graphite in order to learn about atoms, bonding, and the role of structure in controlling the physical properties of solid materials