Dynamic percolation of ferromagnetic regions in phase separated manganites using non-uniform electric fields

Abstract

Thin films of the manganite (La${}_{1-y}$Pr${}_y$)${}_{1-x}$Ca${}_x$MnO${}_3$ exhibit dynamic phase coexistence with micrometer scale, fluid-like ferromagnetic metallic (FMM) regions interspersed in a charge-order insulating (COI) background. It has been previously reported that a uniform electric field realigns the fluid-like FMM regions due to a phenomenon similar to dielectrophoresis. Here we report that non-uniform electric fields have a stronger effect on the FMM regions as expected from the dielectrophoresis model. The dynamic percolation of the FMM regions is observed over a wider range of temperatures compared to the results in a uniform field. Additionally, in a non-uniform electric field, the time required for dynamic percolation along the magnetic hard axis ($t_{\mathrm{B}}$) decreased with increasing applied voltage ($V_{\mathrm{A}}$) as a power law, $V_{\mathrm{A}}^{-\delta }$ with $\delta \approx 5$ while $\delta <2$ for a uniform electric field. Our results in a non-uniform electric field provide strong evidence in favor of the dielectrophoresis model and a unique method for manipulating micrometer-sized ferromagnetic regions using electric fields.

6 pages, 5 figures

References in corpus (6)

• Discovery of intrinsic ferromagnetism in 2D van der Waals crystals
• Coexisting charge modulation and ferromagnetism produces long period phases in manganites: new example of electronic soft matter
• Effect of strain and electric field on the electronic soft matter in manganite thin films
• Single domain to multi-domain transition due to in-plane magnetic anisotropy in phase separated (La${}_{0.4}$Pr${}_{0.6}$)${}_{0.67}$Ca${}_{0.33}$MnO${}_3$ thin films
• Highly anisotropic resistivities in the double-exchange model for strained manganites
• Dielectrophoresis model for the colossal electroresistance of phase-separated manganites