Direct Imaging of Dynamic Glassy Behavior in a Strained Manganite Film

TL;DR

This study uses near-field microwave microscopy to directly visualize and analyze the dynamic glassy behavior and phase separation in a strained manganite film, revealing temperature-dependent switching and freezing phenomena.

Contribution

It provides the first high-resolution imaging of the strain-driven glassy state in manganites, linking microscopic phase behavior with macroscopic magnetic properties.

Findings

Direct visualization of phase separation in manganite film.

Observation of temperature-dependent phase switching and freezing.

Correlation between microscopic configurations and magnetization data.

Abstract

Complex many-body interaction in perovskite manganites gives rise to a strong competition between ferromagnetic metallic and charge ordered phases with nanoscale electronic inhomogeneity and glassy behaviors. Investigating this glassy state requires high resolution imaging techniques with sufficient sensitivity and stability. Here, we present the results of a near-field microwave microscope imaging on the strain driven glassy state in a manganite film. The high contrast between the two electrically distinct phases allows direct visualization of the phase separation. The low temperature microscopic configurations differ upon cooling with different thermal histories. At sufficiently high temperatures, we observe switching between the two phases in either direction. The dynamic switching, however, stops below the glass transition temperature. Compared with the magnetization data, the phase separation was microscopically frozen, while spin relaxation was found in a short period of time.