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Thermodynamic modelling of CVD of the superconducting phases in the Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O systems is reviewed. Both MOCVD and halide CVD are considered. The results are discussed in terms of calculated CVD stability diagrams. The influence of deposition parameters, including selection of precursors, on the existence and extension on those stability regions, where the superconducting phases can be deposited, is described. The results of the thermodynamic modelling are compared with experimental investigations. The agreement between thermodynamics and experiments is satisfactory, indicating that thermodynamic modelling can be used as a guide to predict the optimum deposition conditions.

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Abstract  

Metalorganic complexes of copper have been synthesized by modifying the ligand in the β-diketonate class of compounds. Detailed thermal analysis of several β-diketonate complexes of copper has been carried out to evaluate their suitability as precursors for chemical vapor deposition (CVD). A comparison of their relative volatilities has been made by determining their sublimation rates at different temperatures. Thermal analyses of these complexes reveal significant differences among their volatilities and decomposition patterns.

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By means of a tensimetric flow method and a static method with a silica-membrane zero gauge, the dependence of vapour pressure on temperature was obtained for tris(2,4-pentanedionato)ruthenium(III), Ru(aa)3, and tris(1,1,1-trifluoropentane-2,4-dionato)ruthenium(III), Ru(tfa)3. The thermodynamic characteristics of vaporization and sublimation of these complexes were determined. The processes of thermal decomposition of the vapour of the compounds in vacuum, hydrogen and oxygen were investigated by using mass spectrometry in the temperature range 170–550‡C for Ru(aa)3 and 150–620‡C for Ru(tfa)3. The threshold temperatures of the stability of the vapour of the complexes and the rate constants of the thermolysis processes were determined. The main gaseous products of the thermal decomposition and the dependences of their composition on the presence of hydrogen and oxygen were established.

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Fluorophenyl derivatives of elements II-VI groups

Phase transitions thermodynamics and growing films by CVD

Journal of Thermal Analysis and Calorimetry
Authors: L. Zelenina, T. Chusova, Yu. Stenin, and V. Bakovets

Abstract  

The enthalpies and temperatures of melting of RSi(CH3)3, R4Si, R3P, R3As, R3Sb, R3Bi, R2Te and R2Hg (R=C6F5) were obtained by scanning calorimetry measurements. The pressure of the saturated and unsaturated vapors of RSi(CH3)3, R2Si(CH3)2, R4Si, R3Ga, R3P, R3As, R3Sb, R3Bi, R2Te and R2Hg has been measured by the static method with a membrane-gauge manometer. It was established that all investigated substances proceeded to vapor as monomers. Equations approximating the dependences of saturated vapor pressures on temperature and the enthalpies and entropies of vaporization were obtained. Grafite films with silicon intercalated up to 25 at.% were grown by CVD using R4Si as a precursor. These films showed semiconductor properties in the temperature interval 80–300 K.

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Processing thin films for advanced applications, for instance in electronics and optoelectronics, involves several steps starting from precursor synthesis and ending up with the devices. Especially when optimizing the first steps of this chain of processes, thermoanalytical techniques play an important role. The review will focus on the main chemical deposition methods (CVD, ALE, spray pyrolysis, sol-gel) giving selected examples of problem-solving by thermal analysis. The techniques discussed are TG, DTA/DSC, EGA and their combinations. High-temperature X-ray diffraction (HTXRD) is also a powerful tool for in situ studies of thin films. The examples are taken from solar cell, superconductor and flat panel electroluminescent display technologies.

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Abstract  

The coupling of a quadrupole mass spectrometer (QMS) via a heated capillary to a commercial thermogravimetric analyser is described. The amu and temperature ranges available were up to 1000 amu and 1500°C, respectively. The system was evaluated with test compounds, yielding gaseous species in the m/z range of 17-80, and then used for the study of thermal behaviour of scandium dipivaloyl methanate or Sc(thd)3 which is discussed in detail. Sc(thd)2 appears as the major Sc-containing species with m/z=411 in the gas phase at 200-300°C.

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Introduction Cardiovascular disease (CVD) is responsible for approximately 45% deaths in patients under hemodialysis, but its pathogenesis is very complex [ 1 ]. The event incidence of CVD is high in the first few weeks after initiation of

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Physiology International
Authors: P. L. Latchman, G. Gates, J. Pereira, R. Axtell R, K. Gardner, J. Schlie, Q. Yang, T. Yue, A. Morin-Viall, and R. DeMeersman

Introduction Cardiovascular disease (CVD) is still a main cause of health loss worldwide [ 32 ]. Although high peripheral blood pressure (PBP) increases the risk for CVD [ 30 ], research suggests that irrespective of patients having similar PBP

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Introduction Chronic kidney disease (CKD) is a significant public health problem worldwide with increasing prevalence and poor outcomes such as cardiovascular disease (CVD), end-stage renal disease (ESRD), and mortality

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.C. Battaile D.J. Srolovitz J.E. Butler 1997 Molecular view of diamond CVD growth Journal of

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