Relation between structure, charge ordering and magnetotransport properties in <script type="math/tex">Nd_{0.5}Ca_{0.5}Mn_{1-x}Cr_{x}O_{3}</script> manganites

Schuddinck, W.; Van Tendeloo, G.; Barnabé, A.; Hervieu, M.; Raveau, B.

doi:10.1016/S0304-8853(99)00720-9

Title

Relation between structure, charge ordering and magnetotransport properties in $Nd_{0.5}Ca_{0.5}Mn_{1-x}Cr_{x}O_{3}$ manganites

Author

Schuddinck, W.

Van Tendeloo, G.

Barnabé, A.

Hervieu, M.

Raveau, B.

Abstract

The relationships between incommensurability, charge ordering and magnetotransport properties in Nd0.5Ca0.5Mn1-xCrxO3 manganites have been studied by electron diffraction and lattice imaging versus temperature with 0.02 less than or equal to x less than or equal to 0.07. All compositions show an incommensurate superstructure over the whole temperature domain, despite the fact that they are ferromagnetic and conductive below 140 K, The q-vector (1/2 - delta)a* decreases with increasing temperature for all compositions x. For a given temperature q also decreases with x. Lattice images obtained at low temperature give a clear view of the characteristics of the incommensurate structure. They also provide a better understanding of the charge ordering process. The low-temperature form of the Cr-doped manganites is not a perfectly doubled cell [[2a(p)root 2 x 2a(p) x a(p)root 2]], but defects inducing a tripled cell occur pseudo-periodically. (C) 2000 Elsevier Science B.V. All rights reserved.

Language

English

Source (journal)

Journal of magnetism and magnetic materials. - Amsterdam

Source (book)

Symposium G Material Physics Issues and Applications of Magnetic Oxides, at the E-MRS Spring Meeting, JUN 01-04, 1999, Strasbourg, France

Publication

Amsterdam : 2000

ISSN

0304-8853

DOI

10.1016/S0304-8853(99)00720-9