2008/08/31 by Yu-Zhong Zhang, Yu‐Zhong Zhang, Harald O. Jeschke +2 · 2 citations
Chemistry · Materials Science · Physics and Astronomy · #Electronic and Structural Properties of Oxides #Inorganic Chemistry and Materials #Rare-earth and actinide compounds #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.101.136406
published as Phys. Rev. Lett. 101, 136406 (2008) · 4 pages, 4 figures, accepted in PRL
arxiv created 2008/08/31 · openalex publication_date 2008/09/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Using Car-Parrinello molecular dynamics we investigate the behavior of the low-dimensional multiorbital Mott insulator TiOCl under pressure. We show that the system undergoes two consecutive phase transitions, first at Pc from a Mott-insulator to a metallic phase in the ab plane with a strong Ti-Ti dimerization along b. At a pressure Pc' > Pc the dimerization disappears and the system behaves as a uniform metal. This second transition has not yet been reported experimentally. We show that the insulator-to-metal transition at Pc is driven by the widening of the bandwidth rather than structural changes or reduction of crystal field splittings and it shows a redistribution of the electronic occupation within the t2g bands. Our computed pressure-dependent lattice parameters are consistent with experimental observations and the existing controversy on the change of crystal symmetry at high pressures is discussed.