[15p-D221-1~14] 9.5 新機能材料・新物性

▼ [15p-D221-7] Computational Investigation of Strongly Correlated Yttrium, Europium-based Ternary Hydrides

〇(D)Abdul Ghaffar¹、Peng Song¹、Kenta Hongo²、Ryo Maezono¹ (1.Info Sci-JAIST、2.RCACI-JAIST)

キーワード：Evolutionary algorithm, Ternary Hydride, Strongly correlated materials

Eu-based binary hydrides have been found to exhibit strong magnetic properties due to the complex interaction of localized 4-f electrons in Eu-atoms. Motivated from the recent trend of discovery and synthesis of ternary hydrides from the admixture of two binary phases, using the evolutionary algorithm, we have theoretically investigated the existence of ternary phases YEuH_x (x = 8, 10, 12, 14, 16, 18, 20) formed from YH_x and EuH_y binaries. Our ternary-hull analysis revealed novel ternary hydrides namely Pm-YEuH₁₈, P1-YEuH₁₂, Cmmm-YEuH₈ at 200GPa and Pm-YEuH₈ at 100GPa, for which we confirmed their thermodynamic stability. These compounds exhibit cage-like clathrate H-sublattice structure even for very low symmetry phases such as P1 and Pm without H₂ molecular units. Electron-phonon interaction is found to be weak, nevertheless, our magnetic ordering calculation reveals that P1-YEuH₁₂ and Pm-YEuH₁₈ show antiferromagnetic ordering, whereas Cmmm-YEuH₈ and Pm-YEuH₈ possess ferromagnetic ordering having absolute magnetic moment as high as 6.3 µ_B/Eu-atom.