Gradual charge order melting in Bi0.5Ca0.5MnO3 induced by ultrahigh magnetic field

TL;DR

This study investigates how ultrahigh magnetic fields induce gradual melting and reformation of charge order in Bi0.5Ca0.5MnO3, revealing complex magnetic phase transitions and constructing a detailed B-T phase diagram.

Contribution

It provides new insights into the magnetic phase transitions and charge order dynamics in Bi0.5Ca0.5MnO3 under ultrahigh magnetic fields, highlighting the coexistence of multiple order parameters.

Findings

Charge order melts at high magnetic fields above 100 T.

Metamagnetic transitions become broad and vanish below 70 K in ascending fields.

Clear metamagnetic transition persists in descending fields below 70 K.

Abstract

We have investigated the magnetic properties of Bi0.5Ca0.5MnO3 under ultrahigh magnetic fields by magnetization measurements. This compound shows the metamagnetic transition which indicates the magnetic field induced charge order melting at the room temperature T = 293 K. We reveled that the temperature dependence of the critical field, where the highest critical field is higher than 100 T. At low temperatures, it has been found that the metamagnetic transitions become broad and vanish in the field ascending process below 70 K. On the other hand, in the field descending process, a clear metamagnetic transition is observed even below 70 K. This unusual behavior can be understood as the gradual charge order melting by magnetic field, and its simultaneous reformation. A coexistence of multiple order parameters can account for the observed characteristic dynamics of the first order phase transition. Finally, we constructed the B-T phase diagram with the unusual critical feature at ultrahigh magnetic fields.