New phase transition in Na2Ti2As2O revealed by Raman scattering

Article

关键词: BILBAO CRYSTALLOGRAPHIC SERVER;    FUNCTIONAL PERTURBATION-THEORY;    TOTAL-ENERGY CALCULATIONS;    WAVE BASIS-SET;    PNICTIDE-OXIDES;    DENSITY-WAVE;    CHARGE;    NA(2)TI(2)PN(2)O;    NA2TI2SB2O;    DATABASES;   

DOI  :  10.1103/PhysRevB.93.140501

来源: SCIE

【 摘 要 】

We performed a Raman scattering study of Na2Ti2As2O. We identified a symmetry breaking structural transition at around T-s = 150 K, which matches a large bump in the electrical resistivity. Several new peaks are detected below that transition. Combined with first-principles calculations, our polarization-dependent measurements suggest a charge instability driven lattice distortion along one of the Ti-O bonds that breaks the fourfold symmetry and more than doubles the unit cell.

【 授权许可】

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