Neutron Diffraction Study of La3Ni2O7: Structural Relationships Among n=1, 2, and 3 Phases Lan+1NinO3n+1

✍ Scribed by Christopher D. Ling; Dimitri N. Argyriou; Guoqing Wu; J.J. Neumeier

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 384 KB
• Volume: 152
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2000.8721

✦ Synopsis

Structural relationships among the n ‫؍‬ 1, 2, and 3 members of the Ruddlesden+Popper series La n؉1 Ni n O 3n؉1 are used to predict a lowering of symmetry in the n ‫؍‬ 2 phase, subsequently observed and re5ned against neutron powder di4raction data. Resistivity and magnetic susceptibility measurements are presented for n ‫؍‬ 2 and 3 that suggest the possibility of a further symmetry lowering at low temperature, such as occurs for n ‫؍‬ 1; however, no evidence for this is found in low-temperature neutron data. Re-re5nement of the n ‫؍‬ 3 phase reveals signi5cant strain within the perovskite-type layers that appears to increase with n. This strain is used to explain the absence of low temperature phase transformations for n > 1. In the absence of a phase transformation, possible origins for the resistivity and susceptibility anomalies are considered.