Magnetic properties of the insulating ferromagnetic phase in strained Pr_0.6Ca_0.4MnO_3 thin films

TL;DR

This study investigates the magnetic phases of strained Pr_0.6Ca_0.4MnO_3 thin films, revealing coexistence of insulating phases and surface-induced ferromagnetic metallic states at low temperatures.

Contribution

It provides new insights into the surface and bulk magnetic behaviors of strained manganite thin films using combined magnetization and MOKE measurements.

Findings

Coexistence of ferromagnetic and antiferromagnetic insulating phases below 120K.

Surface of stretched film exhibits metastable ferromagnetic metallic phase at low fields.

Bulk ferromagnetic phase forms at higher magnetic fields (~4T).

Abstract

Bulk magnetization in Pr_{0.6}Ca_{0.4}MnO_3 thin films with tensile (SrTiO_3) and compressive (LaAlO_3) substrate-induced strain is compared to the magnetooptical Kerr effect (MOKE) measurements. In the absence of an external magnetic field, in both films, a stable ferromagnetic insulating majority phase coexists with an antiferromagnetic insulating phase below ~120K. MOKE measurements indicate that at 5K a metastable ferromagnetic metallic (FM) phase is formed at the surface of the stretched film in a magnetic field below 1.1T already, while in the bulk the FM phase starts to form in the field above ~4T in both films.