Iridium Metal Thin Films and Patterned IrO₂ Nanowires Deposited Using Iridium(I) Carbonyl Precursors

Abstract

Highly volatile iridium(I) carbonyl complexes (1-5) with three anionic fluorinated chelates, namely ketoiminate, aminoalkoxide, or iminoalkoxide, have been synthesized and their physical properties relevant to CVD are evaluated. A single-crystal Xray diffraction (XRD) study on Ir(CO) 2 (amakNMe 2 ) (3) confirms a square-planar geometry with two cis-orientated carbonyl ligands. Metallic iridium, polycrystalline IrO 2 thin films, or even patterned IrO 2 nanowires are deposited using Ir(CO) 2 (hfdaN n Pr) (5) as the CVD precursor. A systematic investigation of the deposition of IrO 2 nanowires is conducted, showing a close correlation of observed crystallite morphology with applied system pressure, underlying growth surface, and deposition temperature. Of particular importance, tilted and vertically aligned IrO 2 nanowires are obtained on LiTaO 3 (012) and LiNbO 3 (100) surfaces under a pressure of 30 Torr of oxygen at 425°C. The morphology and structural composition of the IrO 2 are confirmed by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and XRD analyses.

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“…Two distinct peaks, representing the 4f 7/2 and 4f 5/2 spin states were evident for all 4 GPMs, with binding energies at 61.4, 51.5, 72.0 and 45.6 eV for the 4f 7/2 spin state of G–Ir, G–Os, G–Pt and G–Re, respectively. These values largely correspond to the binding energy of the respective metal elements (G–Ir and G–Pt) and metal oxides (G–Os and G–Re) based on previous studies,31–34 suggesting that the metals are most likely existing in different environments for different metal–graphene hybrids. In addition, the atomic percentages of the metal present in each material are summarized in Table 1 as well, with iridium present in the largest amount in the hybrid material as compared to the other three materials.…”

Metal–Organic Derivatives with Fluorinated Ligands as Precursors for Inorganic Nanomaterials

“…On the other hand, the dimeric compound [Me 2 In{OC(CF 3 ) 2 CH 2 NHCH 2 CH 2 -OMe}] 2 contains a centrosymmetric, four-membered In 2 O 2 ring, where each indium metal atom adopts a distorted trigonal bipyramidal geometry with two methyl groups being in equatorial positions ( Figure 6). 40 A number of other metal complexes (Ti, 70 Zr, 70 Hf, 70 Ru, 39 Pd, 38 Ir, 215 and Cu 37,43 ) based on fluorinated amino-and imino-alkoxide ligands have also been reported. X-ray diffraction studies revealed a monomeric structure in all cases, with the anticipated coordination according to the type of ligand framework.…”

Multidentate fluorinated alkoxide ligand platforms for oxophilic metal centers: from MOCVD source reagents to polymerizationcatalysts

“…In turn, they proved to be valuable precursors for deposition of thin films made of quite pure Pd, 16 Ir, 17 Ru, 18 and Cu 19 metals with a low level of carbon and oxygen impurities, as well as polycrystalline IrO 2 thin films, or even patterned IrO 2 nanowires. 17 Gallium derivatives Ga{OL} 2 Cl, where LO = OC(CF 3 ) 2 -CH 2 NMe 2 , OC(CF 3 ) 2 CH 2 C(Me)=NMe, were similarly prepared from GaCl 3 and the corresponding ligand sodium salt (Scheme 10). 20 Single-crystal X-ray diffraction studies revealed mononuclear compounds in a trigonal-bipyramidal (tbp) geometry with chloride and alkoxy groups occupying the equatorial sites and the nitrogen donors located at the axial positions.…”