Electronic structure of a mixed valence system: Eu 3 O 4

摘要: The optical reflectivity of single crystals ${\mathrm{Eu}}_{3}$${\mathrm{O}}_{4}$ has been investigated in the photon energy range between 0.03 and 12 eV. dielectric functions have derived by means a Kramers-Kronig analysis interpreted with lattice vibrations interband transitions from initial ${\mathrm{Eu}}^{2+}$, ${\mathrm{Eu}}^{3+}$, $2{p}^{6}$ states into crystal-field-split $5d$ bands. In addition intra $4{f}^{6}$ observed commented on. Coulomb correlation ${\mathrm{Eu}}^{2+}$ ${\mathrm{Eu}}^{3+}$ found experimentally. Optical transmission measurements at low temperatures revealed blue shift absorption edge for above N\'eel point ${T}_{N}$ zero external magnetic fields red larger than critical field ${H}_{c}=2.4$ kOe, confirming metamagnetic phase. is to be 5.2\ifmmode\pm\else\textpm\fi{}0.2 K.