Achieving tunable emitting YAl3(BO3)4:Eu phosphors by substituting cations (Sr2+, Ca2+, Ga3+, In3+) and controlling BO3 group polarizability

To explore the influence of the luminescence characteristics and valence state of Eu ions, a series of YAl3(BO3)4−m(PO4)m:0.05Eu, Y0.925−xACxLxBO:0.05Eu, Y0.925−yASyLyBO:0.05Eu, Y0.925−zAGzBO:0.05Eu and Y0.925−wAIwBO:0.05Eu phosphors are synthesized.

Développement complet de la polarisabilité des molécules tétraédriques XY4

A new model of polarizability is presented consistent with the Hamiltonian of tetrahedral molecules XY4. Using a coupling scheme in the Td group, polarizability operators are obtained up to any order of approximation for all vibration–rotation bands of any symmetry. This model leads to an unique formula for matrix elements of these operators. We also give the general expression for the Raman intensity of a transition.

Anisotropic Polarizabilities of Tin(IV)-Containing Groups

Electric birefringences , dipole moments and refractivities are reported for a series of organotin compounds. From these are deduced molecular polarizability anisotropies which, with data from Raman band intensities, can be dissected to give the anisotropic polarizabilities for component tin-containing groups. The results fit reasonably within a 'valence-optical' scheme of group polarizability additivity. Regular trends are observed in the directional polarizabilities of groups containing the Group 4b elements Si, Ge and Sn.