The influence of the top-contact metal on the ferroelectric properties of epitaxial ferroelectric Pb ( Zr 0.2 Ti 0.8 ) O 3 thin filmsIn this study, we discuss the electrical properties of junctions consisting of metal electrodes and Nb-doped SrTiO 3 ͑001͒ single crystals. The junctions formed with large work function metals ͑Ni, Au, Pd, and Pt͒ resulted in rectifying transport. A hysteretic feature was observed in the current ͑I͒-voltage ͑V͒ and capacitance ͑C͒-V characteristics of these junctions upon polarity reversal. The ideal Schottky-Mott rule could not explain the barrier height obtained from the I-V data, indicating the existence of interface states. Analyses of the C-V data revealed that a low dielectric constant layer existed at the interface. The interface states and layers affected the transport and the related resistance switching characteristics of the junctions.

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Due to a larger specific volume of the ferroelectric phase, the antiferroelectric-ferroelectric transition is believed to have an enhanced toughening effect against fracture. The toughening requires a non-recoverable transformation in the crack process zone. Complementary measurement of the crystal symmetry, dielectric constant, field-induced polarization, and Raman spectrum on ceramic Pb0.99Nb0.02 [(Zr0.57Sn0.43)0.92Ti0.08]0.98O3 indicates that the antiferroelectric and the ferroelectric states are equally stable at room temperature. Raman mapping further reveals the presence of the ferroelectric phase in a localized zone at the crack tip after unloading. A significant phase-transition-toughening effect is demonstrated in the antiferroelectric ceramic with both indentation fracture and R-curve experiments. The effect in this model composition leads to toughness values ~50% larger than other antiferroelectric ceramics with similar compositions and 60 ~ 130% higher than ferroelectric Pb(Zr,Ti)O3 ceramics. A simple analysis confirms the toughening effect from both volumetric phase transition and deviatoric domain switching during the transformation. The results suggest that other materials near phase boundaries may have similar high fracture resistance. Keywords Antiferroelectric ceramics; Phase transition toughening; Raman mapping; R-curve Disciplines Ceramic Materials | Electro-Mechanical SystemsComments NOTICE: this is the author's version of a work that was accepted for publication in Acta Materialia . Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Acta Materialia , [62, 114, (2014)

A dog was suspected of having caused a traffic accident. Three hair fragments were recovered from the damaged car and subjected to DNA sequence analysis of the canine mitochondrial D-loop control region. The results were compared to saliva and hair samples from the alleged dog, as well as to control hair samples from four unrelated dogs of different breeds. Two sequence types exhibiting five nucleotide differences in a 377 bp fragment were identified among the four controls. Whereas the evidence hair fragment was identical to the type 1 control sequence, the alleged dog shared the type 2 control sequence except for one position. Thus the dog could be excluded as the origin of the hair fragment. As canine mtDNA appears to exhibit only limited polymorphism, mitochondrial D-loop sequence comparison is currently only suitable for exclusions.