10.1021/cm049234y.s007
Eun Ok Chi
Eun Ok
Chi
Alberto Gandini
Alberto
Gandini
Kang Min Ok
Kang Min
Ok
Lei Zhang
Lei
Zhang
P. Shiv Halasyamani
P. Shiv
Halasyamani
Syntheses, Structures, Second-Harmonic Generating,
and Ferroelectric Properties of Tungsten Bronzes:
A<sub>6</sub>M<sub>2</sub>M‘<sub>8</sub>O<sub>30</sub> (A = Sr<sup>2+</sup>, Ba<sup>2+</sup>, or Pb<sup>2+</sup>; M = Ti<sup>4+</sup>, Zr<sup>4+</sup>, or
Hf<sup>4+</sup>; M‘ = Nb<sup>5+</sup> or Ta<sup>5+</sup>)
American Chemical Society
2004
Ba 6 Hf 2 Nb 8 O 30
hysteresis loops
polarization vs
Ba 6 Zr 2 Ta 8 O 30
material
Cm 2 m
Ferroelectric Properties
Ba 6 Ti 2 Nb 8 O 30
SHG efficiency
Spontaneous polarization values
noncentrosymmetric space groups
Ba 6 Ti 2 Ta 8 O 30
Pb 6 Ti 2 Nb 8 O 30
Ba 6 Hf 2 Ta 8 O 30
P 4 bm
1064 nm radiation
Sr 6 Ti 2 Nb 8 O 30
Ba 6 Zr 2 Nb 8 O 30
532 nm
SHG efficiencies range
tungsten bronze oxides
Pba 2
Sr 6 Ti 2 Ta 8 O 30
compounds exhibit
2004-09-21 00:00:00
Figure
https://acs.figshare.com/articles/figure/Syntheses_Structures_Second_Harmonic_Generating_and_Ferroelectric_Properties_of_Tungsten_Bronzes_A_sub_6_sub_M_sub_2_sub_M_sub_8_sub_O_sub_30_sub_A_Sr_sup_2_sup_Ba_sup_2_sup_or_Pb_sup_2_sup_M_Ti_sup_4_sup_Zr_sup_4_sup_or_Hf_sup_4_sup_M_Nb_sup_5_sup_or_Ta_/3324358
Nine tungsten bronze oxides, A<sub>6</sub>M<sub>2</sub>M‘<sub>8</sub>O<sub>30</sub> (A = Sr<sup>2+</sup>, Ba<sup>2+</sup>, or Pb<sup>2+</sup>; M = Ti<sup>4+</sup>, Zr<sup>4+</sup>, or
Hf<sup>4+</sup>; M‘ = Nb<sup>5+</sup> or Ta<sup>5+</sup>), have been synthesized and characterized. Although structurally
very similar, the nine materials are not isostructural. The materials crystallize in noncentrosymmetric space groups, <i>P</i>4<i>bm</i> (no. 100) for Ba<sub>6</sub>Ti<sub>2</sub>Nb<sub>8</sub>O<sub>30</sub>, Ba<sub>6</sub>Ti<sub>2</sub>Ta<sub>8</sub>O<sub>30</sub>, Ba<sub>6</sub>Zr<sub>2</sub>Nb<sub>8</sub>O<sub>30</sub>,
Ba<sub>6</sub>Zr<sub>2</sub>Ta<sub>8</sub>O<sub>30</sub>, Ba<sub>6</sub>Hf<sub>2</sub>Nb<sub>8</sub>O<sub>30</sub>, and Ba<sub>6</sub>Hf<sub>2</sub>Ta<sub>8</sub>O<sub>30</sub>; <i>Pba</i>2 (no. 52) for Sr<sub>6</sub>Ti<sub>2</sub>Nb<sub>8</sub>O<sub>30</sub> and Sr<sub>6</sub>Ti<sub>2</sub>Ta<sub>8</sub>O<sub>30</sub>; and <i>Cm</i>2<i>m</i> (no. 38) for Pb<sub>6</sub>Ti<sub>2</sub>Nb<sub>8</sub>O<sub>30</sub>. All of the compounds exhibit second-order
nonlinear optical behavior, i.e., second-harmonic generation (SHG), by frequency doubling
1064 nm radiation to 532 nm. The SHG efficiencies range from 10 to 600 × SiO<sub>2</sub>. The reported
materials are also ferroelectric, as demonstrated by hysteresis loops (polarization vs electric
field). Spontaneous polarization values (<i>P</i><sub>s</sub>) range from 0.79 to 12.1 μC/cm<sup>2</sup>. The magnitude
of the SHG efficiency and ferroelectric polarization are strongly dependent on the A, M, and
M‘ cations.