Raman spectroscopic evidence on molecular mercuric bromide in the two-dimensional lattice of (${\mathrm{HgBr}}_2$ ${)}_{0.5}$ ${\mathrm{Bi}}_2$ ${\mathrm{Sr}}_2$ ${\mathrm{CaCu}}_2$ ${\mathrm{O}}_{\mathrm{y}}$s

Polarized Raman spectroscopic experiments have been carried out for the mercuric bromide intercalated ${\mathrm{Bi}}_2$ ${\mathrm{Sr}}_2$ ${\mathrm{CaCu}}_2$ ${\mathrm{O}}_{\mathrm{y}}$ single crystal in order to investigate the evolution of electronic and geometric structures of host and guest upon ${\mathrm{HgBr}}_2$ intercalation. All the present spectra indicate the presence of the symmetric linear ${\mathrm{HgBr}}_2$ molecule in the interlayer space of the intercalate together with an interaction between the intercalated ${\mathrm{HgBr}}_2$ and host lattice, which confirms clearly the previous extended x-ray-absorption fine structure/x-ray-absorption near-edge structure results.