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Updated: Jul 15, 2026

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains
Published on: July 20, 2022
Near-field evidence for ferromagnetic "nanoneedles" in Nd1/2Sr1/2MnO3
Paul W Kolb1, Danilo B Romero, H Dennis Drew
1Laboratory for Physical Sciences, University of Maryland, College Park, Maryland 20740, USA. pkolb@lps.umd.edu
Abstract:
We report on the near-field optical microscopic (NSOM) imaging of single-crystal Nd1/2Sr1/2MnO3 near the first-order phase transition from the CE-type charge-ordered insulator (COI) to the ferromagnetic metal (FMM) at 165 K. Using polarized light, the measurements are sensitive to twin domains through optical anisotropy and to hysteretic inhomogeneous strain associated with the phase transition. Optical evidence for strain relaxation and multiphase coexistence is observed through the transition from 150 to 165 K. The multiphase coexistence is seen as the formation of FMM "nanoneedles" with widths less than 100 nm and lengths of at least several micrometers at temperatures well below TC. The work demonstrates polarized NSOM as a technique for the study of first-order solid-state phase transformations on the nanometer spatial scale.
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