Superconducting TaC nanoparticle-containing ceramic nanocomposites thermally transformed from mixed Ta and aromatic molecule precursors

摘要: We report the structure and synthesis approach for obtaining a ceramic nanocomposite pellet comprising ∼50 nm-sized TaC nanoparticles. A mixture of Ta metal powder carbon precursor 1,2,4,5-tetraphenylethynyl benzene, pelletized by vacuum pressing at 131 MPa, on further thermal treatment with Ar 1400 °C yields such composite. On air oxidation, nanoparticles are converted to Ta2O5 760 °C. Hardness measurements revealed that composite exhibited global hardness in range 1.23–1.57 GPa. However, nanoindentation studies showed that, locally, (∼15 GPa) approached densified ceramic. Superconducting consistently two transitions Tc values 10 K 8.5 K, respectively, corresponded bulk component unknown origin. The results discuss morphological constitutional characterizations nanoparticle-containing