The crystallization kinetics and phase transformation of a transparent Tb3+-doped lithium-aluminum phosphate glass, prepared by melt quenching, were investigated. The energy associated to the glass transition and the crystallization parameters (activation energy for crystallization and Avrami exponent) were evaluated by different methods using the experimental data obtained by differential thermal analysis performed at different heating rates. Using an isoconversional method to determine the change of the activation energy for crystallization with the fraction of crystallization, it was verified that with the increase in the fraction of crystallization from 0.1 to 0.9, the value of the activation energy decreased slightly from  370 to  310 kJ mol -1 and that the Avrami exponent varied from 0.8 to 1, suggesting a surface crystal growth mechanism. Observation of the microstructural evolution of heat-treated glass samples confirmed a surface crystallization process revealing spherulitic crystals constituted mainly by aluminum metaphosphate. © 2014 Springer Science+Business Media New York.

{{A series of new cationic and neutral (Ar-BIAN) copper(I) complexes {[}in which Ar-BIAN = bis(aryl)acenaphthenequinonediimine] was synthesised and characterised by elemental analysis, 1D and 2D NMR spectroscopy and single-crystal Xray diffraction. The cationic complexes of the general formula {[}Cu(Ar-BIAN)L-2]BF4 {[}L-2 = (PPh3)(2) (1), dppe (2), dppf (3), (AsPh3)(2) (4); Ar = 4-iPrC(6)H(4) (a), 4-MeOC6H4 (b), 4-NO2C6H4 (c), 2-iPrC(6)H(4) (d), Ph2PCH2CH2PPh2 (dppe), (Ph2PC5H4)(2)Fe (dppf)] were synthesised by reaction of {[}Cu(EPh3)(4)]BF4 (E = P or As) and equimolar amounts of Ar-BIAN ligands, or by reaction of equimolar amounts of {[}Cu(NCMe)(4)]BF4, 4-iPrC(6)H(4)-BIAN (a) and diphosphanes dppe or dppf, in dichloromethane, whereas the neutral complexes of the types {[}CuX(Ar-BIAN)(EPh3)] {[}X = Cl

CuxS thin films, 80 nm thick, are deposited by vacuum thermal evaporation of sulfur-rich powder mixture, Cu2S:S (50:50 wt.%) with no intentional heating of the substrate. The process of deposition occurs at very low deposition rates (0.1-0.3 nm/s) to avoid the formation of Cu or S-rich films. The evolution of CuxS films surface properties (morphology/roughness) under post deposition mild annealing in air at 270 degrees C and their integration in a thin film transistor (TFT) are the main objectives of this study. Accordingly, Scanning Electron Microscopy studies show CuxS films with different surface morphologies, depending on the post deposition annealing conditions. For the shortest annealing time, the CuxS films look to be constructed of grains with large dimension at the surface (approximately 100 nm) and consequently, irregular shape. For the longest annealing time, films with a fine-grained surface are found, with some randomly distributed large particles bound to this fine-grained surface. Atomic Force Microscopy results indicate an increase of the root-mean-square roughness of CuxS surface with annealing time, from 13.6 up to 37.4 nm, for 255 and 345 s, respectively. The preliminary integration of CuxS films in a TFT bottom-gate type structure allowed the study of the feasibility and compatibility of this material with the remaining stages of a TFT fabrication as well as the determination of the p-type characteristic of the CuxS material. (c) 2013 Elsevier B.V. All rights reserved.

CuxS thin films, 80 nm thick, are deposited by vacuum thermal evaporation of sulfur-rich powder mixture, Cu2S:S (50:50 wt.%) with no intentional heating of the substrate. The process of deposition occurs at very low deposition rates (0.1-0.3 nm/s) to avoid the formation of Cu or S-rich films. The evolution of CuxS films surface properties (morphology/roughness) under post deposition mild annealing in air at 270 degrees C and their integration in a thin film transistor (TFT) are the main objectives of this study. Accordingly, Scanning Electron Microscopy studies show CuxS films with different surface morphologies, depending on the post deposition annealing conditions. For the shortest annealing time, the CuxS films look to be constructed of grains with large dimension at the surface (approximately 100 nm) and consequently, irregular shape. For the longest annealing time, films with a fine-grained surface are found, with some randomly distributed large particles bound to this fine-grained surface. Atomic Force Microscopy results indicate an increase of the root-mean-square roughness of CuxS surface with annealing time, from 13.6 up to 37.4 nm, for 255 and 345 s, respectively. The preliminary integration of CuxS films in a TFT bottom-gate type structure allowed the study of the feasibility and compatibility of this material with the remaining stages of a TFT fabrication as well as the determination of the p-type characteristic of the CuxS material. (c) 2013 Elsevier B.V. All rights reserved.

Phosphorus-doped amorphous silicon thin films, deposited at low temperatures by Plasma Enhanced Chemical Vapour Deposition were used as a dopant source on p-type c-Si substrates. A careful step of dehydrogenation was done in order to maintain the a-Si thin-film integrity. Subsequently, a fine-controlled drive-in of dopant, from the amorphous layer to the crystalline wafer was done, to form the p/n junction, using different time periods and temperatures. Dopant profiling in c-Si wafers as well as dopant concentration in a-Si: H films prior to diffusion, both measured by Secondary Ion Mass Spectrometry, are presented. Junction depths obtained are in the range of 98 nm to 2.4 mu m and surface concentrations are in the range of 1.1 x 10(21) to 4.3 x 10(20) at/cm(3). A dual diffusion mechanism explains the ``kink-and-tail{''} shape found for dopant profile. (C) 2013 Elsevier B.V. All rights reserved.

Phosphorus-doped amorphous silicon thin films, deposited at low temperatures by Plasma Enhanced Chemical Vapour Deposition were used as a dopant source on p-type c-Si substrates. A careful step of dehydrogenation was done in order to maintain the a-Si thin-film integrity. Subsequently, a fine-controlled drive-in of dopant, from the amorphous layer to the crystalline wafer was done, to form the p/n junction, using different time periods and temperatures. Dopant profiling in c-Si wafers as well as dopant concentration in a-Si: H films prior to diffusion, both measured by Secondary Ion Mass Spectrometry, are presented. Junction depths obtained are in the range of 98 nm to 2.4 mu m and surface concentrations are in the range of 1.1 x 10(21) to 4.3 x 10(20) at/cm(3). A dual diffusion mechanism explains the ``kink-and-tail{''} shape found for dopant profile. (C) 2013 Elsevier B.V. All rights reserved.

A model is proposed to describe the decrease of H content in hydrogenated amorphous silicon (a-Si: H), during annealing at a fixed temperature. H content has been measured in several a-Si: H samples ( grown by plasma enhanced chemical vapor deposition) after being submitted to different annealing times at 400 degrees C. Obtained data has been fitted to the proposed model and initial diffusion coefficients of 3.2 x 10(-14) cm(2)/s for intrinsic films and 4.2 x 10(-14) cm(2)/s for n-type films were obtained. Reversely, H content evolution can be predicted during a thermal treatment if diffusion coefficients are previously known. (C) 2013 Elsevier B.V. All rights reserved.

A model is proposed to describe the decrease of H content in hydrogenated amorphous silicon (a-Si: H), during annealing at a fixed temperature. H content has been measured in several a-Si: H samples ( grown by plasma enhanced chemical vapor deposition) after being submitted to different annealing times at 400 degrees C. Obtained data has been fitted to the proposed model and initial diffusion coefficients of 3.2 x 10(-14) cm(2)/s for intrinsic films and 4.2 x 10(-14) cm(2)/s for n-type films were obtained. Reversely, H content evolution can be predicted during a thermal treatment if diffusion coefficients are previously known. (C) 2013 Elsevier B.V. All rights reserved.