XAFS STUDY ON REDUCTION PROCESS OF PAULI-PARAMAGNETIC LANIO3 TO ANTIFERROMAGNETIC LA2NI2O5

被引：10

作者：

MORIGA, T ^{[1
]}

KIKKAWA, S ^{[1
]}

TAKAHASHI, M ^{[1
]}

KANAMARU, F ^{[1
]}

NAKABAYASHI, I ^{[1
]}

机构：

[1] OSAKA UNIV,INST SCI & IND RES,IBARAKI,OSAKA 567,JAPAN

来源：

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS | 1993年 / 32卷

关键词：

XAFS; PEROVSKITE-RELATED STRUCTURE; H2; REDUCTION; OXYGEN-NONSTOICHIOMETRY; JAHN-TELLER EFFECT;

D O I：

10.7567/JJAPS.32S2.764

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

Structural variation in a H-2 reduction process of Pauli-paramagnetic LaNiO3 to antiferromagnetic La2Ni2O5 was investigated by means of XAFS spectroscopy. XANES spectra of LaNiO3-x (0 less-than-or-equal-to x less-than-or-equal-to 0.5) indicate that not the pyramidal coordination but the square-planar one is mainly formed even in an early step on the reduction. The Ni-O distance gradually decreased with an increase of the reducing durations, although the ionic radius of Ni ion should expand with the reduction. This phenomenon may be related to the lattice distortion of the octahedral NiO6 and planar NiO4 with cooperative Jahn-Teller ions of d7-Ni3+ in the low spin state and d9-Ni+, lying in the La2Ni2O5.

引用

页码：764 / 766

页数：3

共 6 条

[1]

COIPAS GJ, 1991, INORG CHEM, V30, P920

[2] REDUCED FORMS OF LANIO3 PEROVSKITE .1. EVIDENCE FOR NEW PHASES - LA2NI2O5 AND LANIO2 [J].