What Coexists with the Ferromagnetic Metallic Phase in Manganites.

摘要

Colossal magnetoresistance, whereby the application of a magnetic field reduces the resistivity of a manganite by orders of magnitude, is generally believed to occur because of coexisting phases. Development of a complete theory to explain the phenomenon requires that the exact nature of these phases be known. We used resonant elastic soft x-ray scattering to examine the superlattice order that exists in La0.35Pr0.275Ca0.375MnO3 above and below the Curie temperature. By measuring the resonance profile of the scattered x-rays at different values of q, we we disentangle the contributions of orbital order and antiferromagnetism to the scattering signal above the Curie temperature. Below the Curie temperature, we see no signal from orbital order, and only antiferromagnetism coexists with the dominant ferromagnetic metallic phase.