Ultra-sharp magnetization steps in perovskite manganites

TL;DR

This paper investigates ultra-sharp, intrinsic step-like metamagnetic transitions in the magnetization and resistivity of Pr0.5Ca0.5Mn0.95Co0.05O3 and related manganites, revealing new insights into their magnetic behavior.

Contribution

It demonstrates that the observed sharp steps are intrinsic properties of the manganites, distinct from previously known transitions, and depend linearly on the cooling field.

Findings

Steps are extremely sharp with width < 0.2 mT.

Transitions occur at critical fields linearly dependent on cooling field.

Similar steps observed in non-Co doped manganites and single crystals.

Abstract

We report a detailed study of step-like metamagnetic transitions in the magnetization and resistivity of polycrystalline Pr0.5Ca0.5Mn0.95Co0.05O3. The steps have a sudden onset below a critical temperature, are extremely sharp (width < 0.2 mT), and occur at critical fields which are linearly dependent on the absolute value of the cooling field in which the sample is prepared. Similar transitions are also observed at low temperature in non-Co doped manganites, including single crystal samples. These data show that the steps are an intrinsic property, qualitatively different from either previously observed higher temperature metamagnetic transitions in the manganites or metamagnetic transitions observed in other materials.