Pressure-induced spin-Peierls to incommensurate charge-density-wave transition in the ground state of TiOCl

• Main Authors: Lee, Young S. (Contributor), Prodi, A. (Contributor), Helton, Joel S. (Contributor), Feng, Yejun (Author)
• Other Authors: MIT Materials Research Laboratory (Contributor), Massachusetts Institute of Technology. Department of Physics (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2010-09-28T18:26:07Z.
• Subjects: Article
• Online Access: Get fulltext

The ground state of the spin-Peierls system TiOCl was probed using synchrotron x-ray diffraction on a single-crystal sample at T=6 K. We tracked the evolution of the structural superlattice peaks associated with the dimerized ground state as a function of pressure. The dimerization along the b axis is rapidly suppressed in the vicinity of a first-order structural phase transition at P[subscript C]=13.1(1) GPa. The high-pressure phase is characterized by an incommensurate charge-density wave perpendicular to the original spin-chain direction. These results show that the electronic ground state undergoes a fundamental change in symmetry, indicating a significant change in the principal interactions.
United States. Dept. of Energy (DE-FG02-07ER46134)
United States. Dept. of Energy (Contract No. DE-AC02-06CH11357)
National Science Foundation (Agreement No. DMR-0454672)