Orbital ordering in LaMnO3: Estimates of structure factors and comparison of measurement methods

B. Jiang, J. M. Zuo, Q. Chen, J. C.H. Spence

Research output: Contribution to journalArticlepeer-review

Abstract

This paper shows that the phenomenon of orbital ordering should be detectable by energy-filtered quantitative convergent-beam electron diffraction (QCBED). The structure factors of LaMnO3 crystals are calculated using a non-spherical atomic scattering model of the Mn3+ ion. Several low-order electron structure factors showed pronounced change with orbital ordering, in which the e1g electron orders in the 3d(3z2 - r2) orbital leaving the 3d(x2 - y2) unoccupied. In contrast, the X-ray structure factors showed very small change. Orbital order is important in transition-metal oxides, including colossal magnetoresistive manganite oxides. The calculations show that by using QCBED it is possible to measure the subtle changes in electron structure factors due to orbital ordering of the e1g electron of the Mn3+ ion in an LaMnO3 crystal. A comparison of methods for structure-factor measurement is given, including Bragg X-ray and γ-ray diffraction, X-ray Pendellösung and critical-voltage methods. New measurements by QCBED of structure factors in rutile are compared with the Bragg X-ray values. These show that QCEBD can provide an accurate extinction-free measurement of low-order structure factors, which is extremely difficult or perhaps impossible when using other methods applied to real crystals.

Original languageEnglish (US)
Pages (from-to)4-11
Number of pages8
JournalActa Crystallographica Section A: Foundations of Crystallography
Volume58
Issue number1
DOIs
StatePublished - 2002

ASJC Scopus subject areas

  • Structural Biology

Fingerprint

Dive into the research topics of 'Orbital ordering in LaMnO<sub>3</sub>: Estimates of structure factors and comparison of measurement methods'. Together they form a unique fingerprint.

Cite this