Steplike Lattice Deformation of Single Crystalline (La$_{0.4}$Pr$_{0.6}$)$_{1.2}$Sr$_{1.8}$Mn$_{2}$O$_{7}$ Bilayered Manganite

TL;DR

This study reveals a sharp, field-induced lattice and magnetic phase transition in a bilayered manganite, linked to orbital frustration, resulting in significant magnetoresistive effects and challenging traditional martensitic explanations.

Contribution

It demonstrates that the ultrasharp transition is driven by orbital frustration rather than martensitic transformation in the manganite.

Findings

Observation of a steplike lattice and magnetization transition.

Identification of orbital frustration as a key factor.

Large decrease in resistance during the transition.

Abstract

We report a steplike lattice transformation of single crystalline (La$_{0.4}$Pr$_{0.6}$)$_{1.2}$Sr$_{1.8}$Mn$_{2}$O$_{7}$bilayered manganite accompanied by both magnetization and magnetoresistive jumps, and examine the ultrasharp nature of the field-induced first-order transition from a paramagnetic insulator to a ferromagnetic metal phase accompanied by a huge decrease in resistance. Our findings support that the abrupt magnetostriction is closely related to an orbital frustration existing in the inhomogeneous paramagnetic insulating phase rather than a martensitic scenario between competing two phases.