In , too, we can find polarized Raman spectra given over the wavenumber range 100-1600 cm -1 . The researchers measured the Raman spectra on single domain crystals. "Numerous independent investigations have demonstrated that two broad asymmetric bands peaked approximately at 275 and 514 cm -1 in the A1(TO) Raman spectrum"; Jiang and coworkers have found "three new weak bands at 986, 1204 and 1480 cm -1 in the Raman spectra of BaTiO3 ... According to the temperature dependence of the Raman scattering intensity and bandwidth, [these bands] are attributed to the second-order Raman spectra of BaTiO3 and the strong bands at 275 and 514 cm -1 in the A1(TO) spectrum are confirmed to be of first order. These facts support the order-disorder model of the ferroelectric phase transitions" .