Magnetization reversal and nanoscopic magnetic-phase separation in La1-xSrxCoO3

Joseph E. Davies, J. Wu, C. Leighton, Kai Liu

Research output: Contribution to journalArticle

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Abstract

The doped perovskite cobaltite La1-xSrxCoO3 (LSCO) has been advanced as a model system for studying intrinsic magnetic phase separation. We have employed a first-order reversal curve (FORC) method to probe the amount of irreversible switching in bulk polycrystalline LSCO as a function of Sr doping, field cooling procedure, and temperature. The value of the FORC distribution ρ is used as a measure of the extent of irreversible switching. For x<0.18, the small values of ρ and its ridgelike distribution along local coercivity (Hc) and zero bias (Hb) are characteristic of noninteracting single domain particles. This is consistent with the formation of an array of isolated nanoscopic ferromagnetic clusters, as observed in previous work. For x≥0.18, the much larger values of ρ, the tilting of its distribution towards negative bias field, and the emergence of regions with negative ρ are consistent with increased long-range ferromagnetic ordering. The FORC distributions display little dependence on the cooling procedure. With increasing temperature, the fraction of irreversible switching determined from the FORC distribution follows closely the ferromagnetic phase fraction measured by La nuclear magnetic resonance. Our results furthermore demonstrate that the FORC method is a valuable first-pass characterization tool for magnetic-phase separation.

Original languageEnglish (US)
Article number134419
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume72
Issue number13
DOIs
StatePublished - Oct 1 2005

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Magnetization reversal
Magnetic separation
Phase separation
magnetization
curves
Cooling
Coercive force
Perovskite
cooling
Doping (additives)
Nuclear magnetic resonance
Temperature
coercivity
nuclear magnetic resonance
temperature
probes

Cite this

Magnetization reversal and nanoscopic magnetic-phase separation in La1-xSrxCoO3. / Davies, Joseph E.; Wu, J.; Leighton, C.; Liu, Kai.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 72, No. 13, 134419, 01.10.2005.

Research output: Contribution to journalArticle

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