Investigating the crystal structure of ZrB2 under varied conditions of temperature, pressure, and swift heavy ion irradiation

Abstract

The influence of temperature, pressure, and swift heavy ions on the structural characteristics of a nano-sized zirconium diboride crystal (43 nm) was investigated using X-ray diffraction and Small-Angle X-ray Scattering/Wide-Angle X-ray Scattering (SAXS/WAXS) powder diffraction methods. Within the temperature range of 300–773 K, alterations in lattice parameters, lattice volume, coefficient of thermal expansion, and the kinetics of water molecule absorption on the active surface of the zirconium diboride crystal were comprehensively analyzed. Furthermore, the mechanism responsible for the structural degradation of absorbed water molecules was elucidated. The degree of amorphization in the ZrB2 nano crystal reached its maximum when subjected to irradiation by fast 132Xe26+ ions with an energy of 167 MeV, at fluences of up to 3.0 × 1014 ions/cm2. Additionally, the expansion mechanism of lattice parameters and the kinetics of the phase transformation process under the influence of swift heavy ions were studied. Notably, pressure variations did not induce a phase transition within the lattice structure. However, when exposed to an 8.0 GPa pressure, the lattice underwent substantial maximum contraction, reducing by up to 20.5 Å3.