Linear optical susceptibilities of the oxoborate (Pb 3O) 2(BO 3) 2WO 4: Theory and experiment
Ali Hussain, Reshak, Prof. Dr.
Auluck, Sushil, Dr.
Kamarudin, Hussin, Brig. Jen. Dato' Prof. Dr.
MetadataShow full item record
The optical susceptibilities have been investigated experimentally and theoretically for a newly synthesized oxoborate, (Pb 3O) 2(BO 3) 2WO 4. The crystal structure is composed of one-dimensional 1 ∞ [Pb 3O] 4+ chains formed by corner-sharing OPb 4 tetrahedra. BO 3 and WO 4 groups are located around the chains to hold them together via Pb-O bonds. The solid-state fluorescence spectrum exhibited a maximum emission peak at around 375.2 nm with excitation light of 280 nm. UV-Vis diffuse reflectance spectra showed a band gap of about 2.9 eV which compares well with our theoretical band gap of about 2.3 eV obtained using the local density approximation and 2.6 eV using the Engel-Vosko's generalized gradient approximation.We have optimized the atomic positions starting from our X-ray diffraction data so as to minimize the forces on each atom.Aremarkable finding is that this crystal possesses a weak anisotropy among three components of the frequency-dependent dielectric function and a small positive birefringence. This indicates that the oxoborate, (Pb 3O) 2(BO 3) 2WO 4, cannot be used to produce second harmonic generation (SHG) and optical parametric oscillation.