Local symmetry breaking in Eu1−xLaxB6

Towards a Single Chemical Model for Understanding Lanthanide Hexaborides

“…43 A later Raman study of several x ≤ 0.2 reported a local symmetry breaking of the boron units. 47 Our model suggests that Eu1-x(La or Yb)xB6 transitions from a mixed-minima state to a mostly single minima state with increasing x, consistent with with the valence transition seen in Sm1-x(La or Yb)xB6. The emergent strong anharmonicity may have a large effect on transport properties.…”

Evidence for a subtle structural symmetry breaking in EuB6

“…These modes correspond to internal displacement of B atoms in the B 6 octahedron [21]. Previous RS works [21][22][23][24][25][26][27][28][29] have reported these modes at ∼780 (T 2g ), ∼1150 (E g ), and ∼1260 (A 1g ) cm −1 . Besides these phonons, additional modes at ∼200 and ∼1400 cm −1 were also reported.…”

Moving the Plasmon of LaB6 from IR to Near-IR via Eu-Doping

“…There have been several publications studying the ability to tune the plasmon of LaB 6 to achieve desired optical properties [ 13 , 14 , 15 ], but little is yet known about how vacancies influence these properties. Research discussing vacancies related to optical and vibrational properties in LaB 6 are very recent [ 19 , 31 ], and though much has been done to study the magnetic and thermoelectric properties of La x Eu 1−x B 6 [ 34 , 35 ], no one until now has synthesized doped hexaborides at low temperatures. Furthermore, only in very recent years have the optical properties of doped MB 6 been explored [ 36 , 37 , 38 ].…”