Neutron diffraction studies of stoichiometric and oxygen intercalated La2NiO4 single crystals
2002; Elsevier BV; Volume: 4; Issue: 5 Linguagem: Inglês
10.1016/s1293-2558(02)01299-2
ISSN1873-3085
AutoresW. Paulus, A. Cousson, G. Dhalenne, J. Berthon, A. Revcolevschi, Shoichi Hosoya, W. Treutmann, G. Heger, Ronan Le Toquin,
Tópico(s)Electronic and Structural Properties of Oxides
ResumoSingle crystal neutron diffraction was used to characterize the structural evolution of electrochemically oxidized La2NiO4+δ crystals as a function of temperature. In order to better describe the disorder of the apical and interstitial oxygen atoms we used the maximum entropy method. There is structural evidence not to attribute a peroxide character between the apical and interstitial oxygen atoms situated in exactly (141414) of the F4/mmm unit cell. We have also reinvestigated the structural phase transition of stoichiometric La2NiO4 crystals at 74 K. The symmetry changes from Bmab to Pccn and remains orthorhombic down to 5 K.
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