Unconventional magnetostriction in layered La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7}: Evidence for spin-lattice coupling above T{sub C}
- Science and Technology Center for Superconductivity and Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
The crystal structure of La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7} has been determined as a function of temperature in magnetic fields of 0 and 0.6 T. There is a significant magnetostriction at the Curie temperature T{sub C}; the a axis contracts ({Delta}a/a={minus}0.018{percent}) while the c axis expands ({Delta}c/c=0.05{percent}). The latter value is larger than that found for perovskite manganites ({Delta}l/l=0.02{percent} at 1 T). No such effect occurs at lower temperatures. The magnetostriction results from changes in individual Mn-O bond lengths. From T{sub C} to {approximately}300 K, bulk magnetization and magnetoresistance measurements indicate the presence of magnetic order not observed in the neutron-diffraction data. This suggests short-range magnetic order in this temperature range. Our structural measurements show that within this temperature interval there is also a weak magnetostriction. {copyright} {ital 1997} {ital The American Physical Society}
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 496777
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 18 Vol. 55; ISSN PRBMDO; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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