Energy Landscapes of Tetragonal Phase of Distinct Modes

1. Switching Induced Super Responses in Nanostructured AlloysArmen G. Khachaturyan, Rutgers University New Brunswick, DMR 0704045 It has been assumed as self-evident that the atomic structure of the precipitates in preci-pitation hardened alloys does not change after their formation. However, if the nanosized low-symmetry precipitate phase has multiple orienta-tion variants, there is no physical reason to ignore a possibility of displacive variant switching within its single-domain precipitates. We developed a theory of two distinct modes of variant switching for tetragonal precipitates. Our analytical calculations and numerical simulations suggested that shape and nano-size of coherent precipitates can substantially reduce and even eliminate the energy barriers of variant switching and thus affect the hysteresis of the giant strain response to external stimuli. Conditions for the search of nanostructured alloys with super func-tionalities such as shape memory,superelasticity, and/or super-magnetostriction have been formulated. Energy Landscapes of Tetragonal Phase of Distinct Modes

2. Switching Induced Super Responses in Nanostructured AlloysArmen G. Khachaturyan, Rutgers University New Brunswick, DMR 0704045 The developed concept of variant switching suggests a potentially untapped source of new functional materials with super functionalities to be used in high-performance sensing and/or acting devices. In particular, the obtained results pave the way for the development of “cheap” magnetostrictors free from rare-earth elements. Our findings have been disseminated to broad audiences of both academic and nonacademic communities by publishing papers in high impact scientific journals, presenting invited talks in leading conferences, and interacting with interested students. We are now closely collaborating with both theoretician and experimentalists of other institutions to advocate and push this newly defined research area of functionalizing nanodispersive alloys , and also to validate our findings and to search for advanced functional materials of this kind. H D B G A I C E F A: Rutgers Univ. B: Carnegie Mellon Univ. C: Univ. of Maryland D: Univ. of Connecticut E: Univ. of Virginia F: Virginia Tech G: Ohio State Univ. H: Michigan Tech. I: Univ. of Cal.-Berkeley J: Univ. of Rouen, France I