Thermal Stability of Pb(C11H19O2)2 Used as the Lead Source in MOCVD

Nagashima, Kuniharu; Funakubo, Hiroshi; Seki, Shigevuki; Sawada, Yutaka; Miura, Yuki; Higuchi, Noboru; Matchida, Hideaki

doi:10.1002/1521-3862(200011)6:6<311::aid-cvde311>3.0.co;2-n

Cited by 5 publications

(1 citation statement)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This technique has been shown to be very fruitful to identify, sometimes in conjunction with a thermodynamic study, the intermediate species playing the role of the effective precursors of the solid deposited, e.g. pyrocarbon [19] , diamond [22] , silicon [23] , silicon carbide [24][25][26] , boron carbide [8] and various oxides SnO2 [27] , BaSrTiO3 [28] , Pb (Zr, Ti) O3 [29] . For the present study of both the B-C and Si-B-C systems, correlations are reported between (1) in-situ FTIR gas phase analysis, (2) characterization of the coatings, (3) kinetic study and, as a conclusion, the various chemical processes possibly involved are discussed.…”

Section: Introductionmentioning

confidence: 99%

Understanding the CVD process of (Si)–B–C ceramics through FTIR spectroscopy gas phase analysis

Berjonneau

Langlais

Chollon

2007

Surface and Coatings Technology

View full text Add to dashboard Cite

B-C and Si-B-C ceramics are used as self-healing matrices in ceramic matrix composites. They can be processed by CVD respectively from BCl3-CH4-H2 and BCl3-CH3SiCl3-H2 precursors under reduced pressure and relatively low temperature. An investigation of the CVD process is presented for the two systems on the basis of a FTIR in situ analysis of the gas phase. By adding a porous substrate with a high internal surface in the hot zone of the reactor, the consumption of specific species is enhanced, revealing the effective precursors of the solid (e.g., HBCl2 giving rise to boron). In order to better understand the mechanisms of the solid formation, correlations are pointed out between the gas phase analysis, the deposition kinetics and the properties of the coatings. In the B-C system, an amorphous carbon-rich boron carbide (comprising mostly B-C bonds) is obtained according to a heterogeneous reaction between HBCl2 and a carbon effective precursor (e.g. the CH 3  radical), the C content of the coating increasing with the maturation of the hydrocarbon (i.e. with increasing temperature and PCH4). In the Si-B-C system, two chemical processes compete against each other. The first one, occurring at low temperature (800-900°C), is similar to that involved for the B-C system. The second one, gradually prevailing at higher temperature (900-1000°C), is governed by the formation of Si-C bonds according to a heterogeneous reaction between hydrocarbons and chlorosilanes. This process competes with the formation of B-C bonds and gives rise to SiC nanocrystals for the highest temperatures (T > 1000°C), in a kinetic regime controlled by the mass transfers.

show abstract

Section: Introductionmentioning

confidence: 99%

Understanding the CVD process of (Si)–B–C ceramics through FTIR spectroscopy gas phase analysis

Berjonneau

Langlais

Chollon

2007

Surface and Coatings Technology

View full text Add to dashboard Cite

show abstract

Tin(II) and Lead(II) 4‐Acyl‐5‐pyrazolonates: Synthesis, Spectroscopic and X‐ray Structural Characterization

et al. 2004

View full text Add to dashboard Cite

Novel tin(II) β‐diketonate Sn(Q)2 complexes [HQ = 1‐R1‐3‐R3‐4‐R4(C=O)‐pyrazol‐5‐one; HQC: R1 = Ph, R3 = Me, R4 = Cy; HQS: R1 = Ph, R3 = Me, R4 = CHPh2; HQL: R1 = Ph, R3 = Me, R4 = CH2Ph; HQT: R1 = Ph, R3 = Me, R4 = CH2tBu; HQE: R1 = Ph, R3 = Me, R4 = Et; HQB: R1 = Ph, R3 = Me, R4 = tBu; HQW: R1 = Ph, R3 = Me, R4 = p‐(tBu)Ph; HQR: R1 = Ph, R3 = Me, R4 = p‐[(CH2)5CH3]Ph; HQN: R1 = p‐NO2Ph, R3 = Me, R4 = Ph; HQM: R1 = Me, R3 = Me, R4 = Ph; HQD: R1 = Me, R3 = Me, R4 = Me; HQP: R1 = Ph, R3 = Ph, R4 = Ph; HQG: R1 = Ph, R3 = Ph, R4 = Me; HQF: R1 = p‐CF3Ph, R3 = Me, R4 = Ph; HQH: R1 = p‐CF3Ph, R3 = Me, R4 = Me] have been isolated and characterized by single‐crystal X‐ray diffraction analyses, IR, 1H, 13C, 119Sn NMR and 119Sn Mössbauer spectroscopy, ESI mass spectrometry, conductivity and molecular weight measurements. The tin complexes SnQ2 are air‐stable, contrary to equivalent compounds of classical β‐diketones, and adopt mononuclear pseudo‐trigonal‐bipyramidal structures (pSnO4, where p is a stereochemically active lone electron pair) in which both ligands chelate a single metal center, as confirmed in the X‐ray crystal structure of Sn(QL)2. This structure fits a trend for all “SnO4” compounds: Sn−O(primary) and Sn−O(secondary) bonds are associated with small O(primary)−Sn−O(primary) and wide O(secondary)−Sn−O(secondary) bond angles. The reactivity of Sn(QT)2 toward RI (R = Me or Et) and CrCO6 has been investigated. The compounds PbQ2 (HQ = HQT, HQB, HQW, HQD) have been also synthesized and the X‐ray structures of Pb(QB)2 and Pb(QT)2 in the solid state determined. These are different from SnQ2 and are composed of “PbO4” moieties with additional interactions from neighboring units to produce polymeric forms. Compound Pb(QT)2 is unusual in having the metal−O(pyrazolonato) bond longer than the metal−O(acyl) one, probably due to a Pb−arene interaction with a neighboring phenyl ring. The sterically less hindered Pb(QD)2 reacts with phen (1,10‐phenanthroline) yielding the mixed ligand complex [Pb(QD)2(phen)]. In this work, in addition to the different coordination numbers expressed by Sn and Pb, associated with the larger covalent radius of the latter, the binding mode of 4‐acyl‐5‐pyrazolonates to Pb is syn whereas for Sn it is anti. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

show abstract

Metals – Gas-Phase Deposition and Applications

Lang

Dietrich

2013

Comprehensive Inorganic Chemistry II

View full text Add to dashboard Cite

Thermal Stability of Pb(C11H19O2)2 Used as the Lead Source in MOCVD

Cited by 5 publications

References 8 publications

Understanding the CVD process of (Si)–B–C ceramics through FTIR spectroscopy gas phase analysis

Understanding the CVD process of (Si)–B–C ceramics through FTIR spectroscopy gas phase analysis

Tin(II) and Lead(II) 4‐Acyl‐5‐pyrazolonates: Synthesis, Spectroscopic and X‐ray Structural Characterization

Metals – Gas-Phase Deposition and Applications

Contact Info

Product

Resources

About