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Session S16 - Metals: Defects to Alloys.
ORAL session, Wednesday afternoon, March 05
Room 9C, Austin Convention Center

[S16.003] Structure and magnetic properties of PdHx nano-composite, with hydrogen trapped inside dislocation cores.

Andrei Lipson (Department of Nuclear, Plasma and Radiological Engineering. University of Illinois at Urbana-Champaign), Alexey Bezryadin (Department of Physics. University of Illinois at Urbana-Champaign), Carlos Henry Castaņo G., George Miley (Department of Nuclear, Plasma and Radiological Engineering. University of Illinois at Urbana-Champaign)

Electrochemically cycled, specially prepared palladium samples (Pd and Pd/PdO repetitively loaded and deloaded with hydrogen and deuterium) have been studied with thermal desorption and SQUID magnetic measurements. Cycling of the samples produce a high concentration of dislocations, which trap hydrogen. An activation energy of 0.90 eV is estimated for the hydrogen trapped inside deep dislocation cores. DC magnetic measurements as well as AC susceptibility suggest the presence of a weakly diamagnetic state in Pd samples enriched with hydrogen and deuterium in this manner. The samples showed signatures of antiferromagnetism for temperatures below 100 K in low magnetic fields. The material exhibits ferroelasticity that is ascribed to the presence of domains similar to those in high temperature superconductor ceramics. Some samples exhibit a transition to weak diamagnetism at about 60 K for fields lower than 1 Oe. Imaginary susceptibility shows the presence of a transition, possibly a new phase, that is ascribed to a diamagnetic nano-composite phase.

Part S of program listing