Abstract
Single-crystal x-ray diffraction refinements indicate SrSn2Fe4O11 crystallizes in the hexagonal R-type ferrite structure with non-centrosymmetric space group P63mc and lattice parameters a = 5.9541(2) Å, c = 13.5761(5) Å, Z = 2 (R(F) = 0.034). Octahedrally coordinated sites are randomly occupied by Sn and Fe; whereas tetrahedrally coordinated sites are exclusively occupied by Fe, whose displacement from ideal trigonal-bipyramidal coordination causes the loss of inversion symmetry. DC magnetization data indicate SrSn2Fe4O11 single crystals undergo ferro- or ferri-magnetic order below a transition temperature TC = 630 K with very low coercive fields Hc⊥ = 0.27 Oe and Hc// = 1.5 Oe at 300 K, for applied fields perpendicular and parallel to the c-axis, respectively. The value for TC is exceptionally high, and the coercive fields exceptionally low, among the known R-type ferrites. Enhanced coercivity and thermomagnetic hysteresis suggest the onset of short-range, spin glass order occurs below Tf = 35 K. Optical measurements indicate a band gap of 0.8 eV, consistent with wide-gap semiconducting behavior and a previously established empirical correlation between the semiconducting gap and TC for R-type ferrites based upon Ru.
Original language | English |
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Article number | 055708 |
Journal | AIP Advances |
Volume | 8 |
Issue number | 5 |
DOIs | |
State | Published - May 1 2018 |
Bibliographical note
Funding Information:We would like to thank Dr. Falk Lissner for collecting the x-ray diffraction data and Klaus Wolff for the EDX measurements. Research at the University of Kentucky was supported by U.S. National Science Foundation Grant DMR-1506979.
Publisher Copyright:
© 2017 Author(s).
ASJC Scopus subject areas
- Physics and Astronomy (all)