New phase transition in Na${}_2$Ti${}_2$As${}_2$O revealed by Raman scattering

D. Chen, T. T. Zhang, Z. -D. Song +8

We performed a Raman scattering study of Na${}_2$Ti${}_2$As${}_2$O. We identified a symmetry breaking structural transition at around $T_s=150$ K, which matches a large bump in the ele…