Correlations between Micro- and Nanostructures and Magnetic Transitions in the Ru-Doped Sm0.2Ca0.8MnO3 Manganites

✍ Scribed by M. Hervieu; C. Martin; A. Maignan; B. Raveau

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 426 KB
• Volume: 155
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2000.8882

✦ Synopsis

The electron microscopy study of the Ru-doped manganites Sm 0.2 Ca 0.8 Mn 1؊x Ru x O 3 (04x40.10) shows that the magnetic properties of these materials are strongly correlated to their microstructure. Charge ordering induced by Mn-site doping is shown for the 5rst time, in contrast to what is generally observed. It is shown that Ru-doping paradoxically favors the simultaneous development of ferromagnetic orthorhombic domains and charge-ordered antiferromagnetic domains at low temperature, starting from a monophasic orthorhombic paramagnetic sample at room temperature. This structural phase separation phenomenon at low temperature is explained in terms of two antagonist e4ects introduced by Ru 5؉ substitution: ferromagnetic superexchange interactions and Mn valency.