A reversibly mechanochromic conjugated polymer.

A reversibly mechanochromic conjugated polymer has been developed. The polymer, polydiacetylene (PDA), obtained by thermal polymerization of a diphenyldisulfide-containing bisdiacetylene undergoes a blue-to-green color change upon grinding. The original blue color of the PDA is regenerated via a metastable red-color state by utilizing a thermochromic (heating-cooling) process.

Upshift of phase transition temperature in nanostructured PbTiO3 thick film for high temperature applications.

Thick polycrystalline pure PbTiO3 films with nano size grains were synthesized for the first time by aerosol deposition. Annealed 7 μm thick films exhibit well-saturated ferroelectric hysteresis loops with a remanent polarization and coercive field of 35 μC/cm(2) and 94 kV/cm, respectively. A large-signal effective d33,eff value of >60 pm/V is achieved at room temperature.

Co and Fe doping effect on negative temperature coefficient characteristics of nano-grained NiMn2O4 thick films fabricated by aerosol-deposition.

Spinel structured highly dense NiMn2O4-based (NMO) negative temperature coefficient (NTC) thermistor thick films were fabricated by aerosol-deposition at room temperature. To enhance the thermistor B constant, which represents the temperature sensitivity of the NMO thermistor material, Co and Co-Fe doping was applied. In the case of single element doping of Co, 5 mol% doped NMO showed a high B constant of over 5000 K, while undoped NMO showed -4000 K.