Synthesis and molecular structures of cobalt(II) β-diketonate complexes as new MOCVD precursors for cobalt oxide films

Growth Kinetics, Composition, and Morphology of Co3O4 Thin Films Prepared by Pulsed Liquid‐Injection MOCVD

“…[2,12±23] Different Co II b-diketonate complexes, such as Co(acac) 2 (acac = 2,4-pentanedionate), [2,12±18] Co-(thd) 2 (thd = 2,2,6,6-tetramethyl-3,5-heptanedione), [19] Co(hfac) 2 -2 H 2 O (hfa = CF 3 C(O)CHC(O)CF 3 ), [20] and Co(hfac) 2 -2 H 2 O-tetraglyme adducts (tetraglyme = 2,5,8,11, 14-pentaoxapentadecane), [21] have been used as organometallic precursors to prepare thin films of CoO, Co 3 O 4 , or a mixture of both phases. The recently developed technique of pulsed liquid injection (PI) MOCVD has been previously applied for the preparation of Co 3 O 4 films by using Co(acac) 2 , Co(thd) 2 , and new adducts such as Co(acac) 2 -tetraglyme, [22,23] Co(thd) 2 -tetraglyme, [22,23] Co(acac) 2 -TME-DA (N,N,N¢,N¢-tetramethylethylenediamine), [22] [Co(acac) 2 (DMAPH)] 2 (1-dimethylamino-2-propanol), [23] and Co-(acac) 2 (DMAEH) (2-dimethyaminoethanol). [23] In this paper we report on the preparation and characterization of Co 3 O 4 layers grown on silicon substrates by PIMOCVD using Co(thd) 2 and monoglyme solvent.…”

“…The recently developed technique of pulsed liquid injection (PI) MOCVD has been previously applied for the preparation of Co 3 O 4 films by using Co(acac) 2 , Co(thd) 2 , and new adducts such as Co(acac) 2 -tetraglyme, [22,23] Co(thd) 2 -tetraglyme, [22,23] Co(acac) 2 -TME-DA (N,N,N¢,N¢-tetramethylethylenediamine), [22] [Co(acac) 2 (DMAPH)] 2 (1-dimethylamino-2-propanol), [23] and Co-(acac) 2 (DMAEH) (2-dimethyaminoethanol). [23] In this paper we report on the preparation and characterization of Co 3 O 4 layers grown on silicon substrates by PIMOCVD using Co(thd) 2 and monoglyme solvent. Special attention has been given to the composition, structural, and morphological characterization, highlighting the influence of deposition parameters such as solution concentration, deposition temperature, and oxygen ratio in the reaction atmosphere.…”

Synthesis and characterisation of highly dispersed Ni/SiO2 catalysts prepared by gas-phase impregnation/decomposition (GPI/D) of a Ni(II) ?-diketonate precursor complex

“…An alternative approach for the deposition of welldefined species has recently been applied to the preparation of thin metal films through Metal-Organic Chemical Vapour Deposition (MOCVD) of TMCs [12,13]. In this approach, the precursor complex to be evaporated contains an ancillary Lewis base ligand that allows, on the one hand, the coordinative saturation of the precursor and, on the other hand, is sufficiently labile to be easily exchanged with the surface Lewis-base groups of the substrate or support.…”

A Study on the Development of CVD Precursors VI-Thermal Properties of Co(III) β-Diketonates

“…Many cobalt (II) and (III) compounds such as salts (CoI 2 , Co(OCO-CH3)2, Co(NO3)3) and complexes (Co2(CO)8, Cp2Co and related derivatives) have been utilized but no successful results have been obtained. 4 Well-known Co β-diketonates such as Co(acac)2, Co(acac)3 (acac = 2,4-pentanedionate) and Co(tmhd)2 (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionate) 6 had been used as CVD/ALD precursors but they suffers some drawbacks such as oligomeric nature 7 and limited shelf life. 4 Co(tmhd)2 and ozone have been successfully utilized to grow thin films of Co3O4 [5(c)] or epitaxial growth of cobalt oxide by ALD.…”

“…9 Co β-diketonates with fluorinated substituents such as hfa (hfa = hexafluoroacetylacetonate) have been utilized and new complexes with coordinated water such as Co(hfa)2·2H2O and Co(hfa)2·2H2O·L (L= oxygenated base) have drawn much attention but uncontrolled decomposition or premature reactions in CVD/ALD processes limited further application[5(a), (b), 10]. Co(II) β-diketonates with various N-donor Lewis bases such as N,N,N',N'-tetramethylethylenediamine (TMEDA) and 1-dimethylamino-2-propanol (DMAPH) 4,7 have shown favorable properties such as higher chemical stability, longer shelf life, and higher volatility and preliminary CVD experiments proved promising features for cobalt oxide nanosystems.…”