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arXiv · 1209.1209

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

S. Rößler·Dona Cherian·W. Lorenz·M. Doerr·C. Koz·C. Curfs·Yu. Prots·U. K. Rößler·U. Schwarz·Suja Elizabeth·S. Wirth
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Abstract

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.

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S. Rößler, Dona Cherian, W. Lorenz, M. Doerr, C. Koz, C. Curfs, Yu. Prots, U. K. Rößler, U. Schwarz, Suja Elizabeth, S. Wirth. 2012-09-06. First-order structural transition in the magnetically ordered phase of Fe1.13Te. https://doi.org/10.1103/physrevb.84.174506

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