Employing a comprehensive structure search and high-throughput first-principles calculation method on 1561 compounds,the present study reveals the phase diagram of Lu-H-N.In detail,the formation energy landscape of Lu...Employing a comprehensive structure search and high-throughput first-principles calculation method on 1561 compounds,the present study reveals the phase diagram of Lu-H-N.In detail,the formation energy landscape of Lu-H-N is derived and utilized to assess the thermodynamic stability of each compound that is created via element substitution.The result indicates that there is no stable ternary structure in the Lu-H-N chemical system,however,metastable ternary structures,such as Lu_(20)H_(2)N_(17)(C2/m)and Lu_(2)H_(2)N(P3m1),are observed to have small E_(hull)(<100 meV/atom).It is also found that the energy convex hull of the Lu-H-N system shifts its shape when applying hydrostatic pressure up to 10 GPa,and the external pressure stabilizes a couple of binary phases such as LuN_9 and Lu_(10)H_(21).Additionally,interstitial voids in LuH_(2)are observed,which may explain the formation of Lu_(10)H_(21)and LuH_(3-δ)N_ε.To provide a basis for comparison,x-ray diffraction patterns and electronic structures of some compounds are also presented.展开更多
基金Chinese Academy of Sciences(Grant Nos.CAS-WX2023SF0101 and XDB33020000)the National Key R&D Program of China(Grant Nos.2021YFA1400200 and 2021YFA0718700)。
文摘Employing a comprehensive structure search and high-throughput first-principles calculation method on 1561 compounds,the present study reveals the phase diagram of Lu-H-N.In detail,the formation energy landscape of Lu-H-N is derived and utilized to assess the thermodynamic stability of each compound that is created via element substitution.The result indicates that there is no stable ternary structure in the Lu-H-N chemical system,however,metastable ternary structures,such as Lu_(20)H_(2)N_(17)(C2/m)and Lu_(2)H_(2)N(P3m1),are observed to have small E_(hull)(<100 meV/atom).It is also found that the energy convex hull of the Lu-H-N system shifts its shape when applying hydrostatic pressure up to 10 GPa,and the external pressure stabilizes a couple of binary phases such as LuN_9 and Lu_(10)H_(21).Additionally,interstitial voids in LuH_(2)are observed,which may explain the formation of Lu_(10)H_(21)and LuH_(3-δ)N_ε.To provide a basis for comparison,x-ray diffraction patterns and electronic structures of some compounds are also presented.
