Synthesis, crystal structure, and optical properties of a new lead barium borate, PbBa 2 (B 3 O 6 ) 2

Crystal structure of the solid solution Ba8.35Pb0.65(B3O6)6

“…The Ba-O bond lengths of the Ba2O 9 polyhedron range from 2.766 (3) to 3.030 (3) Å , with a mean distance of 2.869 Å (Table 1). A similar environment for Ba is observed in the crystal structures of Na 3 Ba 2 (B 3 O 6 ) 2 F (Zhang et al, 2015), PbBa 2 (B 3 O 6 ) 2 (Li et al, 2014) and -BBO (Wu et al, 2002). Each of the Ba2O 9 polyhedra shares edges with adjacent Ba2O 9 polyhedra to form six-membered rings that are arranged in corrugated layers extending parallel to (001) (Fig.…”

“…Whereas the title compound Ba 8.35 Pb 0.65 (B 3 O 6 ) 6 crystallizes in space group R3, Ba 7.87 Pb 1.13 (B 3 O 6 ) 6 was solved and refined in space group R32 on the basis of single crystal X-ray diffraction data (Wu et al, 2012); the lattice parameters of both compounds are very similar. Ba 2 Pb(B 3 O 6 ) 2 on the other hand was reported to crystallize either in space group R3 with lattice parameters in the same range as the previous two structures (single crystal X-ray diffraction data; Li et al, 2014) or in space group R3c with a doubled c axis in comparison with the other structures (powder X-ray diffraction data using the Rietveld method; Tang et al, 2015). All four crystal structures are characterized by an alternating stacking of cationic and anionic (001) layers along [001], as shown in Fig.…”

“…It is interesting to compare the structure of Ba 8.35 Pb 0.65 (B 3 O 6 ) 6 with those of the related solid solutions Ba 7.87 Pb 1.13 (B 3 O 6 ) 6 (Wu et al, 2012) and Ba 2 Pb(B 3 O 6 ) 2 (Li et al, 2014;Tang et al, 2015). Whereas the title compound Ba 8.35 Pb 0.65 (B 3 O 6 ) 6 crystallizes in space group R3, Ba 7.87 Pb 1.13 (B 3 O 6 ) 6 was solved and refined in space group R32 on the basis of single crystal X-ray diffraction data (Wu et al, 2012); the lattice parameters of both compounds are very similar.…”

“…4b), responsible for the SHG effect. In Ba 2 Pb(B 3 O 6 ) 2 (Li et al, 2014), the B 3 O 6 rings are parallel to each other, distributed layer upon layer along [001], and the B 3 O 6 rings in neighbouring layers point in exactly opposite directions ( Fig. 4c), just like in the title compound (Fig.…”

Contribution of lone-pairs to birefringence affected by the Pb(ii) coordination environment: a DFT investigation

“…Recently, lead barium borate PbBa 2 (B 3 O 6 ) 2 has been synthesized by standard solid-state reaction 25 It is interesting to note that the birefringence values of α-BBO and Na 3 Ba 2 (B 3 O 6 ) 2 F are 0.122 and 0.115 at 532 nm, respectively 6 , while the reported birefringence of PbBa 2 (B 3 O 6 ) 2 is only 0.08 at 532 nm 25 . Due to the similar coparallel B 3 O 6 density in these crystals, it may be supposed that the birefringence of the PbBa 2 (B 3 O 6 ) 2 crystal is underestimated.…”