Dispersant-assisted preparation of ultra-fine HfB2 powder

Various HfB2 powders were prepared by coprecipitation method combined with carbothermal reduction method, and were characterized by XRD, SEM, TEM, XPS, NMR, FTIR, TGA-DSC, etc. using the instrument platform of the Chinese Academy of Sciences to obtain the original experimental data. Philips X’Pert powder X-ray diffractometer using CuKα (PANalytiacl X’Pert-Pro MPD,USA, λ = 0.15419 nm) radiation. Field emission scanning electron microscope (FESEM, Hitachi SU8020, Japan) and field emission transmission electron microscope (FETEM, Tecnai G2 F20, USA) were used to study the microscopic morphology and structure of samples. An X-ray photoelectron spectrometer (XPS, KRATOS AXIS SURPRA+, Japan) was performed to investigate the valence bonds and surface chemical status of the samples. Thermogravimetric-differential thermal analysis (TGADSC) was performed in an argon atmosphere at a heating rate of 5 ◦C/ min (METTLER-TOLEDO, TGA/DSC 3+, Switzerland). Fourier transform infrared (FTIR, Thermo Nicolet Corporation, NEXUS G2192, USA) analysis was performed in the range of 500–4000 cm- 1 using the KBr pellet method. Nitrogen and oxygen analyzer (LECO, ON836 series elements analyzer, USA) was used to determine the oxygen content of the samples. 1H Nuclear Magnetic Resonance (1H NMR) spectra were taken on Avance 400 spectrometer (Bruker, AVANCE 400, USA) with Methanol-D4 as the solvent and chemical shift references for 1H NMR.The experiment was completed from September 2021 to August 2022.