First-order structural transition in the magnetically ordered phase of Fe1.13Te

Autor: Rößler, S., Cherian, Dona, Lorenz, W., Doerr, M., Koz, C., Curfs, C., Prots, Yu., Rößler, U. K., Schwarz, U., Elizabeth, Suja, Wirth, S.
Rok vydání: 2012
Předmět:
Zdroj: Phys. Rev. B 84, 174506 (2011)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevB.84.174506
Popis: Specific heat, resistivity, magnetic susceptibility, linear thermal expansion (LTE), and high-resolution synchrotron X-ray powder diffraction investigations of single crystals Fe1+yTe (0.06 < y < 0.15) reveal a splitting of a single, first-order transition for y < 0.11 into two transitions for y > 0.12. Most strikingly, all measurements on identical samples Fe1.13Te consistently indicate that, upon cooling, the magnetic transition at T_N precedes the first-order structural transition at a lower temperature T_s. The structural transition in turn coincides with a change in the character of the magnetic structure. The LTE measurements along the crystallographic c-axis displays a small distortion close to T_N due to a lattice striction as a consequence of magnetic ordering, and a much larger change at T_s. The lattice symmetry changes, however, only below T_s as indicated by powder X-ray diffraction. This behavior is in stark contrast to the sequence in which the phase transitions occur in Fe pnictides.
Comment: 6 pages
Databáze: arXiv