Precursor influence on the raman spectrum of KNNLiTaLa0.01 prepared by two different methods

This work presents a study of ceramics with the (K0.44Na0.52Li0.04)0.97La0.01Nb0.9Ta0.1O3 composition through their Raman spectra. In previous studies [1], this composition has shown good permittivity and piezoelectric parameter values that justify a deeper investigation. Two sets of samples of these ceramic compounds were prepared using different methods. The first set was prepared using a classical solid-state reaction of oxides and carbonates, as described in Ref. [2]. The second set was prepared using the NaNbO3 precursor. The Raman spectra of the samples obtained by the direct ceramic method consisted of 5 modes. In contrast, the spectra of the samples obtained using the precursor showed a shift of the wavenumber of the A1g(nu 1) mode peak towards lower values and consisted of seven modes with the appearance of two additional modes, F1u(nu 3) and F2g(nu 4). Notably, using the precursor preparation route led to important improvements with a more straightforward method than Saito et al. [3].