Magnesium β-ketoiminates as CVD precursors for MgO formation

Abstract

The synthesis and characterization of bis (ketoiminato) Complexes 3a-c were used as MOCVD precursors for the deposition of thin MgO films on silicon substrates. It was found that only with 3a,c thin, dense and rather granulated MgO layers of thicknesses between 28-147 nm were produced. The as-deposited MgO layers were characterized by SEM, EDX, and XPS measurements and the thicknesses of the as-deposited layers were measured by Ellipsometry and SEM cross-section images. Apart from magnesium and oxygen a carbon content between 3-4 mol% was determined.

Conductive and Catalytic VTe2@MgO Heterostructure as Effective Polysulfide Promotor for Lithium–Sulfur Batteries

“…34 X-ray photoelectron spectroscopy (XPS) measurement was also carried out to evaluate the chemical states of assynthesized VTe 2 @MgO. 35 The XPS survey spectrum suggests the presence of Mg, O, V, and Te within the VTe 2 @MgO sample (Figure S4). The high-resolution Mg 1s spectrum displays one single peak, indicating the existence of Mg−O bonding (Figure 2l).…”

“…In addition, the weak signal locating at 89 cm –1 is associated with the symmetry point of E g phonon . X-ray photoelectron spectroscopy (XPS) measurement was also carried out to evaluate the chemical states of as-synthesized VTe 2 @MgO . The XPS survey spectrum suggests the presence of Mg, O, V, and Te within the VTe 2 @MgO sample (Figure S4).…”

Invisible Surface Oxygen Vacancies in a Thin MgO Film: Impacts on the Chemical Activity and Secondary Electron Emission

“…Methods like high-thermal treatment under ultrahigh vacuum (UHV), dehydroxylation at high temperature, single-crystal cleavage under UHV, electron–ion bombardment, and photoirradiation generate low-coordinated defective and radiation defects in large quantities and provide no way of studying the intrinsic nonstoichiometric defects. ,, In this case, there is increasing interest in depositing the film by chemical means. Among others, the MOCVD process has evident advantages and, as is known, is able to produce polycrystalline, nanosized, uniform, and single-oriented MgO films operating at 720–800 K as well as layers with quite high secondary electron emission coefficients (SEECs) in the region of low energies of primary electrons. ,, On the negative side, MOCVD, like the chemical process, suffers from the lack of data on gas-phase formation via interaction reactions between the precursor volatile species and oxygen. Thus, only a good understanding of the surface chemistry makes MOCVD an attractive alternative for generating surface and single oxygen vacancies in thin films.…”

“…Matching operating conditions, such as the temperature of the evaporator, carrier and O 2 gas flow rates, total reactor pressure, etc., were selected based on our previous experiments and literature sources where the MOCVD process was realized under conditions close to ours. ,,, An O 2 flow rate of 16.7 sccm was best suited to provide the desired crystallinity, density, and C contamination of the films growing with an acceptable rate. The actual oxygen content, depending on the gas-phase dynamics inside the reactor, remained unknown.…”

“…Among others, the MOCVD process has evident advantages and, as is known, is able to produce polycrystalline, nanosized, uniform, and singleoriented MgO films operating at 720−800 K as well as layers with quite high secondary electron emission coefficients (SEECs) in the region of low energies of primary electrons. 20,33,34 On the negative side, MOCVD, like the chemical process, suffers from the lack of data on gas-phase formation via interaction reactions between the precursor volatile species and oxygen. Thus, only a good understanding of the surface chemistry makes MOCVD an attractive alternative for generating surface and single oxygen vacancies in thin films.…”