Investigation of metamagnetic transition in nanosized FeRh structures

Nanosized iron-rhodium islands of various sizes have been successfully prepared on MgO substrate by masked molecular beam epitaxy. Nuclear scattering of nanofocused synchrotron radiation was used to map the islands, and in-situ measure their magnetic states and metamagnetic phase transition. The findings demonstrated a pronounced size dependency in the metamagnetic behavior of the FeRh, as the size of the islands decreased, the metamagnetic phase transition changes until finally it disappears completely at certain threshold size. This suppression effect suggests that finite-size scaling plays a significant role in determining the magnetic characteristics of FeRh at the nanoscale. These results provide insight into the fundamental mechanisms behind size-dependent magnetic phase transitions in FeRh nanostructures, which likely arise due to increased surface-to-volume ratios, altered atomic coordination, and oxidation-based effects.