Structural evidence of magnetic field induced devitrification of kinetically arrested antiferromagnetic phase in La0.175Pr0.45Ca0.375MnO3: A Low-temperature high-magnetic field x-ray diffraction study

TL;DR

This study uses low-temperature high-magnetic field x-ray diffraction to reveal how magnetic fields induce structural changes and devitrification in phase-separated La0.175Pr0.45Ca0.375MnO3, highlighting strong magneto-structural coupling.

Contribution

It provides direct structural evidence of magnetic field induced devitrification of kinetically arrested phases in LPCMO manganite, expanding understanding of phase transition dynamics.

Findings

Magnetic field induces irreversible ferromagnetic phase below 25K.

Partial reversibility of phase transformation observed between 39-65K.

Constructed H-T phase diagram consistent with magnetic measurements.

Abstract

The low-temperature and high-magnetic field (2K, 8T) powder x-ray diffraction (LTHM-XRD) measurements have been carried out at different temperatures (T) and magnetic fields (H) to investigate the structural phase diagram for phase separated La0.175Pr0.45Ca0.375MnO3 (LPCMO) manganite. The antiferromagnetic (AFM) P21/m insulating phase undergoes field induced transformation to ferromagnetic (FM) Pnma metallic ground state below its AFM ordering temperature (220K) in zero-field cooling (ZFC) from room temperature. At temperature greater than 25K, the field induced FM Pnma phase remained irreversible even after complete removal of field. However, for T ( 39-65K), the field induced transformation is partially reversible. This behaviour has been attributed to magnetic field induced devitrification of the glass-like arrested AFM P21/m phase to FM Pnma equilibrium phase. The devitrified FM Pnma phase starts transforming back to AFM P21/m phase around ~39K on heating the sample under zero field. Our results corroborate the evidence of strong magneto-structural coupling in this system. An H-T phase-diagram has been constructed based on LTHM-XTD data, which resembles with the one made from magnetic measurements. These results have been explained on the basis of kinetic arrest of first order phase transition and field induced devitrification of the arrested phase.