Vapor Pressures and Sublimation Enthalpies of Nickelocene and Cobaltocene Measured by Thermogravimetry

Vieyra-Eusebio, María Teresa; Rojas, Aarón

doi:10.1021/je200815v

Cited by 34 publications

(20 citation statements)

References 32 publications

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“…This excess can be achieved by increasing the vapor pressure by heating the evaporator or/and by increasing the pulse time. For NiCp 2 , the vapor pressure at 100 • C is 320-370 Pa [56,57], while for Ni(MeCp) 2 , the vapor pressure at 73 • C is 133 Pa [58]. These values are very small; therefore, to pulse the reagents in sufficient excess into the reactor, their heating is necessary.…”

Section: Atomic Layer Deposition Of Nio Thin Filmsmentioning

confidence: 99%

Atomic Layer Deposition of NiO to Produce Active Material for Thin-Film Lithium-Ion Batteries

et al. 2019

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Atomic layer deposition (ALD) provides a promising route for depositing uniform thin-film electrodes for Li-ion batteries. In this work, bis(methylcyclopentadienyl) nickel(II) (Ni(MeCp) 2 ) and bis(cyclopentadienyl) nickel(II) (NiCp 2 ) were used as precursors for NiO ALD. Oxygen plasma was used as a counter-reactant. The films were studied by spectroscopic ellipsometry, scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray reflectometry, and X-ray photoelectron spectroscopy. The results show that the optimal temperature for the deposition for NiCp 2 was 200-300 • C, but the optimal Ni(MeCp) 2 growth per ALD cycle was 0.011-0.012 nm for both precursors at 250-300 • C. The films deposited using NiCp 2 and oxygen plasma at 300 • C using optimal ALD condition consisted mainly of stoichiometric polycrystalline NiO with high density (6.6 g/cm 3 ) and low roughness (0.34 nm). However, the films contain carbon impurities. The NiO films (thickness 28-30 nm) deposited on stainless steel showed a specific capacity above 1300 mAh/g, which is significantly more than the theoretical capacity of bulk NiO (718 mAh/g) because it includes the capacity of the NiO film and the pseudo-capacity of the gel-like solid electrolyte interface film. The presence of pseudo-capacity and its increase during cycling is discussed based on a detailed analysis of cyclic voltammograms and charge-discharge curves (U(C)).NiO nanofilms are produced using various methods [12] such as thermal spraying, pulsed laser deposition, sol-gel, spin-coating, dip-coating, chemical vapor deposition, and atomic layer deposition (ALD). ALD is the most promising technology because it provides control over the thickness and purity of coatings with high precision, and can deposit uniform surface coatings on of complex shape and even porous and high aspect ratio substrates [13][14][15]. This method could be a crucial factor for transition from 2D to 3D solid-state batteries (SSB), which are structured on 3D substrates with high aspect ratio instead of planar substrates. It could increase the energy density of SSB with the same thickness of the electrode to maintain the required conductivity of the layers [16]. ALD is based on a realization of the sequence of chemical reactions between gaseous reagents and the surface species of the substrate, separated in time by purges with an inert gas to prevent uncontrolled reactions between the reactants and the reaction products. Because of the self-limiting nature, this method allows the deposition of films in a layer-by-layer fashion and the control of the thickness with high precision [13].When selecting the deposition conditions via ALD, it is necessary to consider the stability and reactivity of the precursors. Many precursors have been tested for ALD NiO so far, but the most frequently used are shown in Table 1: nickel(II) acetylacetonate (Ni(acac) 2 ), bis(2,2,6,6-tetramethylheptane-3,5dionate)nickel(II) (Ni(thd) 2 ), bis(cyclopentadienyl) nickel(II) (NiCp 2 ), and NiCp 2 -based compounds such as ...

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Section: Atomic Layer Deposition Of Nio Thin Filmsmentioning

confidence: 99%

Atomic Layer Deposition of NiO to Produce Active Material for Thin-Film Lithium-Ion Batteries

et al. 2019

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“…Using the following equation the enthalpy ∆H sub and temperature T sub of sublimation can be determined. 20 ln ቀ݉ ௦௨ ܶ ଵ ଶ…”

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confidence: 99%

Thermal Behavior of Methylammonium Lead-Trihalide Perovskite Photovoltaic Light Harvesters

et al. 2014

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Recently organic–inorganic hybrid perovskites have attracted attention as light harvesting materials in mesoscopic cells. While a considerable number of deposition and formation methods have been reported for the perovskite crystalline material, most involve an annealing step. As such, the thermal behavior of this material and its individual components is of crucial interest. Here, we examine the thermal properties of the CH3NH3PbX3 (X = I or Cl) perovskite using thermogravimetric analysis. The role of the precursors is exposed, and the effect of the formation of excess organic species is investigated. The sublimation behavior of the organic component is intensively scrutinized. Furthermore, differential scanning calorimetry is employed to probe the crystal phase structure, revealing subtle differences depending on the deposition method.

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“…The vapor pressures recorded in Table 3 are all higher than those previously described cobalt-CVD precursors including cobaltocene, [(C 5 H 5 ) 2 Co], 49 , 23 although notably significantly lower than both Co 2 (CO) 9 and alkyl systems [Co 2 (CO) 6 (η 2 -RCCR)] (R = n-C 3 H 7 to n-C 7 H 15 ). 23b Resultantly, compound 1 was chosen as a good candidate for AP-MOCVD experiments owing to its attractive TGA profile, high vapor pressure, and thermal stability.…”

Section: Inorganic Chemistrymentioning

confidence: 61%

Cobalt(I) Olefin Complexes: Precursors for Metal–Organic Chemical Vapor Deposition of High Purity Cobalt Metal Thin Films

et al. 2016

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We report the synthesis and characterization of a family of organometallic cobalt(I) metal precursors based around cyclopentadienyl and diene ligands. The molecular structures of the complexes cyclopentadienyl-cobalt(I) diolefin complexes are described, as determined by single-crystal X-ray diffraction analysis. Thermogravimetric analysis and thermal stability studies of the complexes highlighted the isoprene, dimethyl butadiene, and cyclohexadiene derivatives [(C5H5)Co(η(4)-CH2CHC(Me)CH2)] (1), [(C5H5)Co(η(4)-CH2C(Me)C(Me)CH2)] (2), and [(C5H5)Co(η(4)-C6H8)] (4) as possible cobalt metal organic chemical vapor deposition (MOCVD) precursors. Atmospheric pressure MOCVD was employed using precursor 1, to synthesize thin films of metallic cobalt on silicon substrates under an atmosphere (760 torr) of hydrogen (H2). Analysis of the thin films deposited at substrate temperatures of 325, 350, 375, and 400 °C, respectively, by scanning electron microscopy and atomic force microscopy reveal temperature-dependent growth features. Films grown at these temperatures are continuous, pinhole-free, and can be seen to be composed of hexagonal particles clearly visible in the electron micrograph. Powder X-ray diffraction and X-ray photoelectron spectroscopy all show the films to be highly crystalline, high-purity metallic cobalt. Raman spectroscopy was unable to detect the presence of cobalt silicides at the substrate/thin film interface.

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Vapor Pressures and Sublimation Enthalpies of Nickelocene and Cobaltocene Measured by Thermogravimetry

Cited by 34 publications

References 32 publications

Atomic Layer Deposition of NiO to Produce Active Material for Thin-Film Lithium-Ion Batteries

Atomic Layer Deposition of NiO to Produce Active Material for Thin-Film Lithium-Ion Batteries

Thermal Behavior of Methylammonium Lead-Trihalide Perovskite Photovoltaic Light Harvesters

Cobalt(I) Olefin Complexes: Precursors for Metal–Organic Chemical Vapor Deposition of High Purity Cobalt Metal Thin Films

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