Translating reproducible phase-separated texture in manganites into reproducible two-state

C. ISRAEL,1 L. GRANJA,2 T. M. CHUANG,3,† L. E. HUESO,1,‡ D. SÁNCHEZ,1 J. L. PRIETO,1,§ P. LEVY,2

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

©2008 The American Physical Society

Lugar: NY; Año: 2008 vol. 78 p. 54409 - 54409

0163-1829

In thin-film La0.6Ca0.4MnO3, conducting-tip and magnetic force microscopy reveal a pattern of nanoscalephase separation that is reproducible across cooling runs. This pattern represents the intersection of buriedthree-dimensional filamentary ferromagnetic metallic pathways with the sample surface. As an interlayer incurrent-perpendicular-to-the-plane trilayer devices, this phase-separated material magnetically decouples ferromagneticmetallic La0.7Ca0.3MnO3 electrodes which switch sharply. This yields sharp two-state low-fieldmagnetoresistance that is also reproducible across cooling runs. The reproducibility and the magnitude of theresistance jump are linked to highly resistive
10−12
m2 constrained domain walls in the pathways of thephase-separated interlayer. Phase separation is normally associated with high-field colossal magnetoresistanceand, therefore, its exploitation here to produce low-field effects is unusual.DOI: 10.1103/PhysRevB.78.054409 PACS number
s: 75.47.Lx, 73.43.Qt, 75.60.Ch, 81.16.Rf