Vapour-Phase Synthesis of Submicron Tantalum Carbide

A co-reduction synthesis of superconducting NbC nanorods

“…Furthermore, superconducting NbC nanorods can serve as the building blocks in superconducting nanodevices. Previously, NbC has been prepared by various high-temperature reactions above 1000 • C, such as the direct combination of niobium metal with carbon [2], gas-phase reaction of NbCl 5 with hydrocarbon [3] and carburization of the oxides by carbon or methane-hydrogen mixtures [4,5]. However, these methods cannot produce nanocrystalline NbC.…”

Fabrication of ultrafine TaC powders by mechano-chemical process

“…5, powders heat-treated at 1050 and 1100 8C are composed of single phase, TaC. There are no peaks corresponding to tantalum, tantalum oxide, and Ta 2 C. The TaC was formed completely at about 1050 8C, which is significantly lower than fabrication temperature (1500 8C) of TaC in conventional process [6][7][8][9][10][11][12][13][14]. In the carbothermal synthesis of TaC from a mixture of carbon and tantalum oxide, the overall reaction governing the formation of TaC is Ta 2 O 5 (s)+ 7C(s)Y2TaC(s)+5CO(g) [11].…”

“…Tantalum carbide can be synthesized by the carbothermal reduction of tantalum oxide (Ta 2 O 5 ) powders using carbon [6][7][8][9][10] or polymeric precursors obtained from tantalum alkoxides [11], direct reaction between the Ta metal and carbon [12], and gas phase reaction of TaCl 5 with hydrocarbons [13].…”

Growth of NbC Thin Film Using CH4 as a Carbon Source and Reducing Agent

“…After the growth for 30 min, the Nb-precursor supply line was closed, and the samples were rapidly cooled under the Ar environment. used as a precursor [22,23]. Nb flux can be obtained by heat treatment of NbOx in a reducing atmosphere (hydrogen gas or additives such as NaF); however, this reaction has a disadvantage as a high temperature of 1000 °C (or larger) is required [24][25][26].…”

“…Conventionally, the synthesis of an NbC thin film is performed by the direct reaction between Nb metal and carbon owing to the very high melting point [20,21]. However, as the melting point of Nb reaches 2744 • C, a chemical compound containing Nb such as NbCl 5 (melting point: 205 • C) was used as a precursor [22,23]. Nb flux can be obtained by heat treatment of NbO x in a reducing atmosphere (hydrogen gas or additives such as NaF); however, this reaction has a disadvantage as a high temperature of 1000 • C (or larger) is required [24][25][26].…”