Magnetic and lattice coupling in single-crystal SrFe2As2: A neutron scattering study

TitleMagnetic and lattice coupling in single-crystal SrFe2As2: A neutron scattering study
Publication TypeJournal Article
Year of Publication2009
AuthorsLi HF, Tian W, Zarestky JL, Kreyssig A, Ni N, Bud'ko SL, Canfield PC, Goldman AI, McQueeney RJ, Vaknin D
Journal TitlePhysical Review B
Date Published08/01
ISBN Number1098-0121
Accession NumberISI:000269638500044
Keywordsantiferromagnetic materials, high-temperature superconductors, iron compounds, magnetic hysteresis, magnetic superconductors, magnetic transition temperature, neutron diffraction, order-disorder transformations, remanence, strontium compounds, superconduc

A detailed elastic neutron scattering study of the structural and magnetic phase transitions in single-crystal SrFe2As2 reveals that the orthorhombic (O)-tetragonal (T) and the antiferromagnetic transitions coincide at T-O=T-N=(201.5 +/- 0.25) K. The observation of coexisting O-T phases over a finite temperature range at the transition and the sudden onset of the O distortion provide strong evidences that the structural transition is first order. The simultaneous appearance and disappearance within 0.5 K upon cooling and within 0.25 K upon warming, respectively, indicate that the magnetic and structural transitions are intimately coupled. We find that the hysteresis in the transition temperature extends over a 1-2 K range. Based on the observation of a remnant orthorhombic phase at temperatures higher than T-O, we suggest that the T-O transition may be an order-disorder transition.

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