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In this work, PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2 thin films with (002) preferred orientation were prepared using a pulsed laser deposition technique. The temperature dependence of resistivities ρI(T) was investigated under various applied DC currents. Colossal electroresistance (CER) effects were found in PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2. It was found that the positive CER values of PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2 reach 3816% and 154% for I = 1.00 μA at 10 K, respectively. In addition, the ρI(T) cycle curves of PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2 thin films showed a critical temperature similar to that of PbPdO2 (Tc = 260 K). Particularly, charge transfer between O1− and O2− was confirmed by in situ XPS. Additionally, based on first-principles calculations and internal electric field models, the CER and magnetic sources in PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2 can be well explained. Finally, it was found that thin film samples doped with V and G ions exhibit weak localization (WL) and weak anti-localization (WAL) quantum transport properties. Ion doping leads to a transition from WAL to WL. The study results indicate that PbPdO2, one of the few oxide topological insulators, can exhibit novel quantum transport behavior after ion doping. [ABSTRACT FROM AUTHOR]

Abstract: Direct anodic oxidation of 1,5-dihydroxynaphthalene (DHN), an important derivative of naphthalene, led to the formation of high-quality semiconducting poly(1,5-dihydroxynaphthalene) (PDHN) on stainless steel sheets in boron trifluoride diethyl etherate (BFEE). The onset oxidation potential of DHN in this medium was measured to be only 0.78V vs. SCE, which was lower than that determined in traditional acetonitrile containing 0.1mol/L tetrabutylammonium tetrafluoroborate (0.98V vs. SCE). As-formed PDHN films showed good redox activity and stability, together with interesting electrochromic property from brown (doped) to yellow-green (dedoped). Structural characterization, including FTIR, 1H NMR, and quantum chemistry calculations, indicated that the polymerization of DHN probably occurred at C4 and C8 positions. Moreover, thermal analysis revealed that PDHN displayed better thermal stability than that synthesized by chemical method. The fluorescence spectral studies, together with the electrical tests, showed that PDHN was a good blue light-emitter (fluorescence quantum yield higher than 0.1) with an electrical conductivity of as high as 0.46S/cm. [Copyright &y& Elsevier]

The article discusses a study which determined the process for electrochemical synthesis of poly(6-nitroindole) (P6NI) films of a new conducting polymer, by direct anodic oxidation of 6-nitroindole in boron trifluoride diethyl etherate. The good thermal stability of P6NI films and its potential application in production of electrochemical sensors and green-light-emitting materials are revealed. Also cited is the low oxidation potential onset of 6-nitroindole which was measured at 0.98 volts (V).

In this work, PbPd 0.9 V 0.1 O 2 and PbPd 0.9 Gd 0.1 O 2 thin films with (002) preferred orientation were prepared using a pulsed laser deposition technique. The temperature dependence of resistivities ρ I ( T ) was investigated under various applied DC currents. Colossal electroresistance (CER) effects were found in PbPd 0.9 V 0.1 O 2 and PbPd 0.9 Gd 0.1 O 2 . It was found that the positive CER values of PbPd 0.9 V 0.1 O 2 and PbPd 0.9 Gd 0.1 O 2 reach 3816% and 154% for I = 1.00 μA at 10 K, respectively. In addition, the ρ I ( T ) cycle curves of PbPd 0.9 V 0.1 O 2 and PbPd 0.9 Gd 0.1 O 2 thin films showed a critical temperature similar to that of PbPdO 2 ( T c = 260 K). Particularly, charge transfer between O 1- and O 2- was confirmed by in situ XPS. Additionally, based on first-principles calculations and internal electric field models, the CER and magnetic sources in PbPd 0.9 V 0.1 O 2 and PbPd 0.9 Gd 0.1 O 2 can be well explained. Finally, it was found that thin film samples doped with V and G ions exhibit weak localization (WL) and weak anti-localization (WAL) quantum transport properties. Ion doping leads to a transition from WAL to WL. The study results indicate that PbPdO 2 , one of the few oxide topological insulators, can exhibit novel quantum transport behavior after ion doping.

PbPdO 2 , a gapless semiconductor, can be transformed into a spin gapless semiconductor structure by magnetic ion doping. This unique band-gap structure serves as the foundation for its distinctive physical properties. In this study, PbPd 1- x Mn x O 2 ( x = 0.05, 0.1, 0.15) thin films with (002) preferred orientation were prepared by laser pulse deposition (PLD). The structural, electroresistive and magnetoresistive properties were systematically characterized, and the results suggest that films with different Mn doping ratios exhibit a current-induced positive colossal electroresistance (CER), and the CER values of PbPd 1- x Mn x O 2 thin films increase with the increase of Mn doping concentration. The CER values are several fold magnitudes higher compared to those of the previously reported PbPdO 2 films possessing identical (002) orientation. Combined with first-principles calculation, the underlying influence mechanism of Mn doping on CER is elucidated. In situ X-ray photoelectron spectroscopy (XPS) demonstrates a close correlation between the positive CER and the band gap change induced by oxygen vacancies in PbPd 1- x Mn x O 2 . Additionally, it is observed that Mn-doped films exhibit weak localization (WL) and weak anti-localization (WAL) quantum transport. Moreover, it is found that Mn doping can lead to a transition from WAL to WL; a small amount of Mn doping significantly enhances the weak anti-localization effect. However, with increasing Mn concentration, the WAL effect is conversely weakened. The results of studies suggest strongly that PbPdO 2 , one of the few oxide topological insulators, can display novel quantum transport behavior by ion doping., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)