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Abstract A theoretical model of the Cd/Zn interdiffusion during the growth of different sequences of ZnTe/CdTe layers was developed. The model can predict the values of the growth parameters needed to obtain desired composition profiles from specific ZnTe/CdTe multilayer growth sequences. With these simulations as a guide, Cd x Z n1 - x Te graded composition samples with different Cd profiles and thicknesses were grown. A good agreement was found, demonstrating the possibility of preparing different and predictable Cd content profiles in Cd x Zn 1-x Te graded thin films by the simple isothermal close space sublimation method. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

Abstract: In this work, SiO2 layers containing Ge nanocrystals (NCs) obtained by the hot implantation approach were submitted to an ion irradiation process with different 2MeV Si+ ion fluences. We have investigated the photoluminescence (PL) behavior and structural properties of the irradiated samples as well as the features of the PL and structural recovery after an additional thermal treatment. We have shown that even with the highest ion bombardment fluence employed (2×1015 Si/cm2) there is a residual PL emission (12% from the original) and survival of some Ge NCs is still observed by transmission electron microscopy analysis. Even though the final PL and mean diameter of the nanoparticles under ion irradiation are independent of the implantation temperature or annealing time, the PL and structural recovery of the ion-bombarded samples have a memory effect. We have also observed that the lower the ion bombardment fluence, the less efficient is the PL recovery. We have explained such behavior based on current literature data. [Copyright &y& Elsevier]

Abstract: We present results on the light emission of Si nanocrystals embedded into a SiO2 matrix obtained via ion implantation. As measurement temperature increases, the main photoluminescence peak shows a shift which is consistent with recombination involving confined electronic states of the nanoparticles around 150 – 170 K when the emission shows a sudden blueshift. After that, the usual energy redshift as temperature increases follows again. It was showed before that silicon nanoparticles light emission present a coexistence of localized states (surface or interface, that dominate the emission spectra at room temperature) and confined states (quantum confinement, dominating the low temperature range). In this work we investigate whether this anomaly in the nanoparticle PL peak energy as a function of temperature might be related to some of these localized states. [Copyright &y& Elsevier]

Abstract: In the present paper we report structural and photoluminescence (PL) results from samples obtained by Si implantation into stoichiometric silicon nitride (Si3N4) films. The Si excess was introduced in the matrix by 170keV Si implantation performed at different temperatures with a fluence of Φ=1×1017 Si/cm2. The annealing temperature was varied between 350 and 900°C in order to form the Si precipitates. PL measurements, with a 488nm Ar laser as an excitation source, show two superimposed broad PL bands centered around 760 and 900nm. The maximum PL yield is achieved for the samples annealed at 475°C. Transmission electron microscopy (TEM) measurements show the formation of amorphous nanoclusters and their evolution with the annealing temperature. [Copyright &y& Elsevier]

Abstract: Si nanocrystals (Si NCs) produced by hot implantation present two photoluminescence (PL) bands (at 780 and 1000nm, respectively) when measured at low pump power (∼20mW/cm2). Since each PL band was shown to have different origin we have investigated the passivation effect on them, as well as their PL decay lifetime. PL and time resolved PL measurements have demonstrated that both PL bands present different behavior after the passivation process. We have found that only the 1000nm PL band is strongly influenced by the passivation process in its intensity as well as in its decay lifetime. In addition we have studied samples implanted at 600°C annealed at 1150°C for different time intervals and further passivated. The results show that the passivation effect on the 1000nm PL band is strongly dependent on the preannealing time. [Copyright &y& Elsevier]

Abstract: Using the results of the PRESST-NEXT study, concerning 69,902 health care workers (HCWs) in ten European countries and their answers about job satisfaction, the authors present the analysis of data concerning HCWs working in psychiatry in France (in psychiatric hospitals, general hospitals and private clinics) and in three European countries with a sufficient sample size (Germany, Great-Britain and Slovakia). The first part is descriptive and highlights the age of psychiatric HCWs, and, in France, the relative importance of male and qualified HCWs in psychiatry compared to other departments. The way HCWs perceive their working conditions indicates that physical hardship is not infrequent and that violence is a great concern but that this violence is preventable, and that contrarily to accepted ideas, over half of these HCWs mention a lack of psychological support. Half of the psychiatric HCWs are not satisfied with their existing opportunity of giving patients the care they need. Indeed the study shows that their dissatisfaction with the use of their abilities and their intent on leaving nursing are high in each specialty and in each country the highest being in France. A more detailed analysis of work organisation and content shows that interruptions, lack of time to talk to patients and frequent worries about making mistakes are highly important. The context seems strongly influenced by the bad quality of inter-professional relationships except between direct colleagues, and this difficulty is greater with the administration for French HCWs. As far as work autonomy is concerned, if psychiatric HCWs say they are more autonomous than those working in other departments, we have noticed that in France HCWS have the lowest influence in planning rotas. The mental health status of French HCWs is lower than that of their counterparts in other countries and they declare more mental exhaustions and mental disorders via medical diagnoses. After adjustments relative to age, gender and occupational level, the risk of low job satisfaction score is less frequent in psychiatry compared to that in medical and surgical departments (Odds ratio OR=0.69; 95 % IC 0.58–0.81; P <0.001). The risk of having a high quantitative demand score (OR=0.20; 95 % IC 0.16–0.23; P <0.001) and a high score of uncertainty regarding treatment (OR=0.49; 95 % IC 0.42–0.56; P <0.001) is lower in psychiatry compared to that in medical and surgical departments. Psychiatric HCWs declared being subjected to violence from patients or their relatives at least once a month nearly six times more than HCWs working in intensive care units. Psychiatric HCWs in Great-Britain and France are more exposed to risks as compared to HCWs in intensive care units in their country (OR=9.98; 95 % IC 6.31–15.8; P <0.001 and OR=6.17; 95 % IC 4.82–7.89; P <0.001, respectively). But in these two countries, HCWs working in emergency units are even more at risk. Those working in geriatrics are also a group at risk. HCWs working in psychiatry and in geriatrics in the four countries declared more mental disorders via medical diagnoses than HCWs in intensive care units (Psychiatry OR=1.72; 95 % IC 1.30–2.28; P <0.001 and geriatrics OR=1.51; 95 % IC 1.18–1.94; P <0.001). In the second part of the study two key questions are analysed in depth using multivariate analysis: these are the factors linked with the intent on leaving nursing and the intent on changing institution. Indeed, factors associated in psychiatry with intent on leaving nursing or on changing institution show the major role of the work environment, the key factors here are harassment by superiors, dissatisfaction with work prospects and the use of HCW abilities. In conclusion, the study draws connexions between factors of dissatisfaction of HCWs, patient conditions in psychiatry and the risk of development of violence. [Copyright &y& Elsevier]

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Abstract: The French HCWs who have been studied belong to the French sample of European NEXT Study. This sample consists of 55 public and private institutions in five regions. WAI has been calculated on 4306 subjects out of 5376 because of missing data. More than a third have a moderate or a poor index (29.4% and 5.2%, respectively). Half (50.6%) of the sample have a good index and only 14.9%, an excellent one. The WAI decreases with age: 19.4% of the “less than 30”, 14.6% of the 30–44 years old and 12.3% of the 45+ have an excellent WAI. But, the rate of decrease depends definitely on job demands and especially on physical load. The multivariate analysis showed that in France as well as in the other countries, work demand, uncertainty about treatments, low support from colleagues, and dissatisfaction with psychological support had high odds ratios for a low WAI. Dissatisfaction with physical working conditions and the necessity to maintain uncomfortable postures were the second group of factors with a strong influence on a low WAI. The absence of time for sports or leisure remained strongly linked with a low WAI after an adjustment to the other risk factors. The WAI enables the workplace physician to summarize data which the hospital can use to further its thinking about how to manage jobs and skills. [Copyright &y& Elsevier]

The energy loss of H2 and H3 molecules along the 〈1 1 0〉 and non-aligned directions of Si was measured through the Rutherford backscattering technique in combination with a SIMOX target. The experiments were performed at 300, 500 and 700 keV/atom. The results show the following features: First, the random and channeling molecular stopping powers are larger than the corresponding atomic one. Second, at a given energy per atom, the H3 energy loss is larger than the one of H2. Third, within the experimental errors, the channeling and random molecular stopping powers are equal. Finally, there are strong indications that the contribution of the screened Coulomb explosion to the energy straggling of molecular beam increases with the molecular velocity. [Copyright &y& Elsevier]

Abstract: Up to the present, by using the ion implantation technique, photoluminescence (PL) from Ge nanocrystals (Ge NCs) was obtained by room temperature (RT) Ge implantation into a SiO2 matrix followed by a high temperature anneal. In this way two PL bands were observed, one at 310nm and the second, with much higher yield at 390nm. In the present work we have used another experimental approach. We have performed the Si implantation at high temperature (T i) and then, we have done a higher temperature anneal (T a) in order to nucleate the Ge NCs. With this aim we have changed T i between RT and 600°C. By performing the implantation at T i =350°C we found a PL yield four times higher than the one obtained from the usual RT implantation at the same fluence. Moreover, by changing the implantation fluence between Φ =0.25×1016 and 2.2×1016 Ge/cm2 we observed that Φ =0.5×1016 Ge/cm2 induces a PL yield three times higher as compared to the usual RT implantation fluence. In conclusion, using a hot Ge implantation plus an optimal Ge atomic concentration, we were able to gain more than one order of magnitude in the 390nm PL yield as compared with previous ion implantation results. [Copyright &y& Elsevier]