Interplay between charge, orbital and magnetic order in Pr_{1-x}Ca_xMnO_3

TL;DR

This study uses resonant x-ray scattering to investigate charge and orbital order in Pr_{1-x}Ca_{x}MnO_3, revealing that charge order influences orbital order and that orbital domains are formed rather than long-range order.

Contribution

It provides new insights into the interplay between charge and orbital order, showing charge order drives orbital order and orbital domains form instead of long-range orbital order.

Findings

Charge and orbital order intensities follow the same temperature dependence.

Long-range orbital order is not achieved; orbital domains form.

Charge order fluctuations are more correlated than orbital fluctuations above T_O.

Abstract

We report resonant x-ray scattering studies of charge and orbital order in Pr_{1-x}Ca_{x}MnO_3 with x=0.4 and 0.5. Below the ordering temperature, T_O=245 K, the charge and orbital order intensities follow the same temperature dependence, including an increase at the antiferromagnetic ordering temperature, T_N. High resolution measurements reveal, however, that long range orbital order is never achieved. Rather, an orbital domain state is formed. Above T_O, the charge order fluctuations are more highly correlated than the orbital fluctuations. Similar phenomenology is observed in a magnetic field. We conclude that the charge order drives the orbital order at the transition.