Direct experimental evidence of multiferroicity in a nanocrystalline Zener polaron ordered manganite

TL;DR

This study provides direct experimental evidence of multiferroicity in nanocrystalline Zener polaron ordered manganite, showing size-dependent tunability of ferromagnetism and ferroelectricity coexistence.

Contribution

It demonstrates that reducing particle size enhances ferroelectric response while maintaining Zener polaron order, enabling coexistence of ferromagnetism and ferroelectricity near room temperature.

Findings

Ferroelectricity confirmed in PCMO via remanent polarization measurements.

Nanocrystalline samples show enhanced ferroelectric response.

Size reduction shifts magnetic order from antiferromagnetic to ferromagnetic.

Abstract

We discuss the particle size driven tunability of the coexistence of ferromagnetism and ferroelectricity in Pr0.67Ca0.33MnO3(PCMO) with the help of x ray diffraction, magnetization, impedance spectroscopy, and remanent polarization measurements. The remanent polarization measurements using the positive up negative down method clearly prove the existence of ferroelectricity in PCMO with phase separation between Zener polaron(ZP) ordered P21nm and disordered Pbnm structures. We also find that the ferroelectric response is enhanced in nanocrystalline samples so long as ZP ordering is not destroyed while the long-range antiferromagnetic ordering at low temperature in bulk system is replaced by ferromagnetic correlations in nanoparticles. The conclusion that by reducing the crystallite size it might be possible to make ferromagnetism and ferroelectricity coexist near room temperature should be generally applicable to all ZP ordered manganites.