Electronic and Magnetic Properties Due to Co Ions in La0.9Sr0.1Fe1−xCoxO3

✍ Scribed by H. Nakatsugawa; E. Iguchi

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 353 KB
• Volume: 159
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2001.9187

✦ Synopsis

Variations in physical properties due to Co ions in La 0.9 Sr 0.1 Fe 1؊x Co x O 3 (x4 40.5) in which short-range ferromagnetic orders are expected to work predominantly at a rather large x have been investigated so as to elucidate Co states. dc and ac measurements indicate that a hopping process of small polarons dominates electronic conduction, but there is a large reduction in hopping energy when x increases from 0.1 to 0.5. This reduction is related to the structural transition induced by an increase in Co content. A spin-glass phase due to short-range ferromagnetic orders is recognized for x ‫؍‬ 0.5 in magnetic measurements. A Curie+Weiss relation realized for x ‫؍‬ 0.5 and comparison of the thermopower extrapolated experimentally at TPR with magnitudes estimated theoretically deduce that all or most of Co ions in La 0.9 Sr 0.1 Fe 1؊x Co x O 3 are HS Co 3؉ and IS Co 4؉ ions.