Abstract
Density functional theory has been applied to elucidate the stability of thorium monoxide (ThO). It is found out that the pressure can stabilize the rocksalt phase of ThO, and the transition pressure is estimated between 14 and 22 GPa. The stability of ThO can be attributed due to the gradually filling 5f orbitals at the expense of 7s and 6d electrons in Th metal. For ThO, the pressure induces stronger Th-O bond reflected by the newly established 6d-2p hybridization which is the dominant cause of its stability. The phonon dispersion curves of the rocksalt phase show the positive frequencies which indicates its dynamical stability. Our successful prediction of the stabilization of the metallic ThO has proposed a route to synthesize novel actinide monoxides.
Highlights
Density functional theory has been applied to elucidate the stability of thorium monoxide (ThO)
Our results show that the external pressure plays a dominating role in stabilization ThO
The reaction enthalpy is positive at ambient pressure which suggests that ThO is unstable
Summary
Density functional theory has been applied to elucidate the stability of thorium monoxide (ThO). The nuclear fuels serve the transmutation function by incorporating components from the promising fuel materials In this scenario, Th has been recognized as a powerful alternative for many years[2]. The investigations of current and new actinide oxides play the crucial role in the nuclear fuel cycle in the coming years. It is known from literature that Th is stable in fcc structure up to 100 GPa17, whereas the fluorite (Fm3m) phase of ThO2 transforms to the orthorhombic α-PbCl2 phase at 40 GPa18 These studies imply that no phase transition occurred in the pressure range of 0 ~ 35 GPa. The main aim of the present paper is to study the reaction enthalpy of ThO as a function of pressure in order to evaluate the static stability of ThO. Our results show that the external pressure plays a dominating role in stabilization ThO
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
