New magnetic phase in rb3c60 fullerene in normal state observed in torque experiments

TL;DR

This study uses torque experiments to reveal a new magnetic phase in Rb3C60 fullerene, showing a structural transition and magnetic ordering around 200-250 K linked to Jahn-Teller effects.

Contribution

First application of torque technique to fullerides, identifying a magnetic phase transition and structural change in Rb3C60 in the normal state.

Findings

Detected structural phase transition from s.c. to f.c.c.

Observed magnetic crossover at 200-250 K.

Linked magnetic ordering to Jahn-Teller distortion.

Abstract

For the first time, magnetic properties of fullerides have been studied using a torque technique. Rb3C60 single crystal has been investigated in these experiments. It was shown that this method is sensitive to the structural phase transition from s.c. to f.c.c. structure. A rearrangement of magnetic system in this material was observed at temperature T ~ 200 - 250 K. Our results clearly show, that this effect is a crossover to an ordered magnetic phase related to interaction of magnetic dipoles and is related to the distorted T' site. The effect is discussed in terms of cooperative Jahn-Teller effect.