Neutron diffraction studies of the crystal and magnetic structure of Nd1.5Sr0.5NiO4
| Autor: | Kandalam V. Ramanujachary, John E. Greedan, Guo Liu, Martha Greenblatt, B. W. Arbuckle |
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| Rok vydání: | 1992 |
| Předmět: |
Condensed matter physics
Magnetic structure Chemistry Neutron diffraction Condensed Matter Physics Magnetic susceptibility Electronic Optical and Magnetic Materials Inorganic Chemistry Crystal Tetragonal crystal system Nuclear magnetic resonance Reflection (mathematics) Materials Chemistry Ceramics and Composites Antiferromagnetism Diffuse reflection Physical and Theoretical Chemistry |
| Zdroj: | Journal of Solid State Chemistry. 97:419-426 |
| ISSN: | 0022-4596 |
| DOI: | 10.1016/0022-4596(92)90051-v |
| Popis: | The crystal structure and magnetic ordering of Nd1.5Sr0.5NiO4 which shows a susceptibility maximum at 17 K have been investigated by neutron diffraction. A tetragonal K2NiF4-type structure is confirmed at room temperature with a = 3.7756(3) A and c = 12.485(1) A. A mean NiO distance of 1.986(5) A reflects the presence of equal concentrations of Ni2+ and Ni3+. Low temperature neutron diffraction data to 11 K reveal features not apparent in the bulk susceptibility. Below 50 K a broad, diffuse reflection at Q = 0.835 A−1 is found which can be indexed as (1200) relative to the chemical cell. The intensity of this peak has an unusual temperature dependence with abrupt increases between 25 and 21 K and between 14 and 11 K. The correlation length derived from the peak width decreases from a constant value of 20(4) A between 14 and 21 K to 12(2) A at 11 K. Also at 11 K a resolution-limited reflection appears which can be indexed as (101) on a magnetic cell with aM = √2aCH which is typical for long-range antiferromagnetic order in K2NiF4 structure compounds. The diffuse (1200) reflection is ascribed to short-range magnetic order on the Ni sublattice while the long-range order below 11 K involves most likely NdNi intersublattice coupling. Both forms of order coexist at 11 K. |
| Databáze: | OpenAIRE |
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