Mass Spectrometric Study of Thermolysis Mechanism of Metal Acetylacetonates Vapour

Abstract

The processes of thermal decomposition of aluminium(II1) and scandium(II1) acetylacetonates (Al(aa)3 and Sc(aa)-,)were investigated in the 160-650°C temperature range using a high-temperature molecular beam source with mass spectrometric sampling of the gas phase composition directly at the outlet from the reaction zone. A scheme of thermal decomposition of aluminium(II1) and scandium(II1) acetylacetonates vapour is suggested. It is established that the common mechanism of thermolysis of these complexes is due to the commonness of electronic structure of ions Mg 2f, A I '+, Sc " and Hf 4+. According to the scheme, the process proceeds along three parallel routes, one of them being possible only for complexes possessing more than two Iigands; in this case the gaseous products resulting from cyclic dimerization of ligand fragments are formed. The influence of oxygen and hydrogen on the composit~on of the gaseous products and the mechanism of ther~~iolysis of the complexes vapour are also established. From temperature curves, the effective values of kinet~c parameters in Arrhenius equation are calculated for the first order reaction.

MOCVD and Physicochemical Characterization of (HfO2)x(Al2O3)1‐x Thin Films

“…The proposed scheme of Hf(dpm) 4 vapor decomposition differs from that for thermolysis of Al(acac) 3 vapors. [12] According to this scheme, under the same conditions (at T > 520 8C), one should expect that high carbon content in the condensed phase arises as a result, not only of destruction of the chelate vapor, but also as a result of the fragmentary decomposition of the ligand, which leads to a broad set of gaseous products;…”

“…As it follows from comparison of the decomposition mechanism of Hf(dpm) 4 ( Fig. 1) and Al(acac) 3 [12] the last-mentioned is the source of carbon-containing impurities in the films. The use of the source containing a mixture of both precursors with different volatilities allowed us to involve the possibilities of combinatorial chemistry, and to obtain a set of different compositions of the alloys in one sample.…”

“…1) and Al(acac) 3 . [12] 2.3. Film Structure Figure 3a shows the X-ray diffraction (XRD) patterns of the (HfO) x (Al 2 O 3 ) 1-x and HfO 2 films.…”

Thermodynamic study of CVD–ZrO2 phase diagrams

“…The gaseous and solid chemical species considered in the calculations are summarized in Table 1. These include the significant decomposition products of several metalacetylacetonates reported in the literature [21][22][23][24][25].…”

Mechanistic study of the gas-phase chemistry during the spray deposition of Zn(O,S) films by mass spectrometry

“…Here, zinc acetylacetonate (Zn(acac) 2 ) is applied as the precursor to prepare Zn(O,S) films due to its easy availability and its high volatility. Turgambaeva et al [12] , [13] used high temperature mass spectrometry to study the thermolysis and thermal stability of β-diketonates, such as Sc(acac) 3 , Pb(acac) 2 , Al(acac) 3 , and Cu(acac) 2 . Ismail et al [14] investigated the thermolysis of Zn(acac) 2 by means of differential temperature analysis and thermogravimetry (TGA) and analyzed the products using IR-spectrometry and XRD.…”