Compounds of Thorium and Boron

Wedemeyer, H.

doi:10.1007/978-3-662-06342-2_4

Cited by 2 publications

(7 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The convex hulls of Th 3 B 2 , ThB 2 , Th 3 B 4 , and ThB decrease to 0.078, 0.042, 0.069, and 0.065 eV/atom, and ThB 12 appears on the convex hull line by taking zero-point energy into consideration. The results of the zero-point energy verify the topology of the Th–B binary phase diagram . Sun , found that the E hull of observed metastable phases lower than 0.1 eV per atom above the ground state, which generally can be successfully synthesized in experiments, should be dynamically stable (i.e., the phonon spectra of a metastable phase should has no imaginary frequency) .…”

Section: Results and Discussionsupporting

confidence: 54%

“…The existence of the Th–B binary system had been found through the X-ray diffraction measurements, and, up to now, researchers have identified three known thorium borides, namely, ThB 4 , ThB 6 , and ThB 12 . The syntheses of thorium borides (ThB 4 and ThB 6 ) were first achieved in 1905 by reducing ThO 2 with boron . Available experimental thermophysical data suggested that ThB 4 is a promising ceramic material, and the material properties by uranium doping have also been reported .…”

Section: Introductionmentioning

confidence: 99%

“…10 The syntheses of thorium borides (ThB 4 and ThB 6 ) were first achieved in 1905 by reducing ThO 2 with boron. 11 Available experimental thermophysical data suggested that ThB 4 is a promising ceramic material, and the material properties by uranium doping have also been reported. 12 Konrad et al 13 elaborated the structural characterization for ThB 4 and ThB 6 , confirming that the crystal structure of the tetraboride ThB 4 has a tetragonal lattice isomorphous to UB 4 , and the hexaboride ThB 6 belonging to the space group Pm3̅ m crystallizes in a cubic structure where an octahedron B 6 is formed.…”

Section: Introductionmentioning

confidence: 99%

“…16 In addition to the known Th−B compounds, Dunbar 10 found that the prepared thorium boride films have a stoichiometry similar to that of ThB 2 , as shown by the Auger electron spectrum, but ThB 2 does not correspond to any known Th−B compounds; in addition, the binary compound ThB also cannot be experimentally confirmed at present. 10 B element has a large thermal neutron cross section (3800 barn), while the isotope 11 B has a lower cross section (less than 0.1 barn). 17 As a result, 10 B absorbs a large number of neutrons and the enriched isotope 11 B significantly lessens the probability when B is applied in the fission reactors.…”

Section: Introductionmentioning

confidence: 99%

“…10 B element has a large thermal neutron cross section (3800 barn), while the isotope 11 B has a lower cross section (less than 0.1 barn). 17 As a result, 10 B absorbs a large number of neutrons and the enriched isotope 11 B significantly lessens the probability when B is applied in the fission reactors. Refractory ceramic borides have some precedents as nuclear fuels due to their excellent physical properties.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Evolutionary Search for Novel Thorium Borides toward Advanced Nuclear Fuels

et al. 2022

View full text Add to dashboard Cite

Thorium (Th)-based fuels are considered as promising candidates for generation-IV reactors. To explore potential thorium boride (Th x B y ) structures and to obtain physical properties of these thorium borides, in our work, a variable-composition evolutionary algorithm prediction method implemented in the Universal Structure Predictor: Evolutionary Xtallography code was adopted to search stable binary compounds in the Th−B system. Six stable and metastable Th−B binaries with different chemical compositions were predicted, in which three hitherto-unknown phases ThB 2 , Th 3 B 4 , and ThB were discovered. The electronic, mechanical, and thermal properties of these thorium borides were studied in detail based on the first-principles method. ThB is the only ionic compound, and the other compounds exhibit metallic and covalent properties. All the thorium borides except for Th 3 B 4 exhibit excellent thermal conductivity. In addition, ThB 4 and ThB 12 have outstanding mechanical properties. ThB 2 , ThB 4 , and ThB 12 are expected to be promising candidates for new nuclear fuels due to their appropriate mechanical and thermal properties.

show abstract

Section: Results and Discussionsupporting

confidence: 54%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Evolutionary Search for Novel Thorium Borides toward Advanced Nuclear Fuels

et al. 2022

View full text Add to dashboard Cite

show abstract

Novel thorium borides and their hardness and superconductivity under pressure: Ab initio calculations

Sahoo

Joshi

2023

Journal of Applied Physics

View full text Add to dashboard Cite

With the motivation of searching for new superconductors with better hardness in the Th–B system, we have performed ab initio evolutionary searches for all the stable compounds in this binary system in the pressure range of 0–200 GPa. From our enthalpy of formation calculations, it is found that only ThB4 (Space group No. P4/mbm), ThB6 (Space group No. Pm3¯m), and ThB12 (Space group No. Fm3¯m) compositions are preferred at zero pressure, in accordance with the experimental reports. Under pressure, our calculations predict the thermodynamically stable compositions, ThB (Space group No. R3¯m), Th3B4 (Space group No. R3¯m), ThB2 (Space group No. Amm2), and ThB8 (Space group No. R3¯m) at 54, 19, 35, and 51 GPa, respectively. Furthermore, although the thermodynamical stability of these compounds is predicted to be at high pressures, the possibility of occurrence at 0 GPa due to metastability still exists. The detailed calculations and analysis of the electronic structure and mechanical and thermal properties have been carried out on these materials using the ab initio tool. The P4/mbm phase of ThB4 and the Fm3¯m phase of ThB12 exhibit high hardness of 30.5 and 35.2 GPa under ambient conditions, which is comparable the hard material, B4C. On the other hand, among all the thorium borides, ThB2 shows a high electron–phonon coupling constant of 0.804 and is predicted to have Tc around 12.72 K. In addition, it has been found that the predicted high-pressure compositions, Th3B4 and ThB, display superconductive behavior under pressure. Additionally, various thermophysical quantities such as lattice thermal conductivity, bulk modulus, thermal expansion coefficient, specific heat capacity, and Gibbs free energy under ambient conditions have been determined from these calculations.

show abstract

Compounds of Thorium and Boron

Cited by 2 publications

References 40 publications

Evolutionary Search for Novel Thorium Borides toward Advanced Nuclear Fuels

Evolutionary Search for Novel Thorium Borides toward Advanced Nuclear Fuels

Novel thorium borides and their hardness and superconductivity under pressure: Ab initio calculations

Contact Info

Product

Resources

About