Dresden 2014 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 55: Poster II
MA 55.49: Poster
Freitag, 4. April 2014, 10:30–13:30, P2
Structural and magnetic phase transitions in antiferromagnetic PrCaFeO4 — •Navid Qureshi1, Martin Valldor1,2, Lisa Weber1, Anatoliy Senyshyn3, Yvan Sidis4, and Markus Braden1 — 1II. Physikalisches Institut, Universität zu Köln — 2MPI für Chemische Physik fester Stoffe — 3Technische Universität München, FRM-II — 4Laboratoire Léon Brillouin, C.E.A. Saclay
We present a comprehensive study on PrCaFeO4 using macroscopic methods, neutron and x-ray diffraction as well as inelastic neutron scattering. Two single crystals have been grown which exhibit two structural and one magnetic phase transition as seen from single differential thermal analysis and neutron diffraction. In contrast, the very closely related compound LaSrFeO4 stays tetragonal (I4/mmm) throughout the whole temperature range [1]. The transition temperature and especially the transition regime of the spin reorientation from an in-plane configuration (like in LaSrFeO4) to the c axis is strikingly different between the two samples suggesting a strong influence of the crystal quality on the magnetic properties. Inelastic neutron scattering reveals a smaller anisotropy gap in the low-temperature magnetic phase, whereas the coupling constants only change for the interplane interaction between the two phases. The spin reorientation and the decreasing gap result from an interplay between magnetostriction and spin-orbit coupling closely connected to the temperature-induced structural changes of lattice constants and octahedral tilts.
N. Qureshi et al., Phys. Rev. B 87, 054433 (2013).