Fig. 3: The magnetostriction in the antiferromagnetic state of UO₂—alternate field directions.

a A schematic diagram showing the bulk sample magnetostriction along the <111> direction in a magnetic field applied immediately in the direction opposite to that of the previously applied field (bold blue line). As opposed to Fig. 2a, the sample shows irreversible behavior by instead initially contracting in the <111> direction, but then rapidly switching back to the previous expanding behavior once a threshold field has been surpassed. b The integrated intensity in 2θ for selected fields and at temperature, T = 25 K. As opposed to 2c, the higher 2θ peak is initially larger, but then a change in relative intensities and peak position can be seen. c A plot of the relative strain calculated from the peak positions in the reversed field state at 25 K. The peak corresponding to the dominant strain behavior as determined by the bulk magnetostriction is the blue squares and the secondary peak corresponding to negative strain is the red circles. Note that the curves for positive fields are similar to the data in Fig. 3b. Open symbols are used for rising fields and closed for falling fields. The blue solid line is guide to the eye. The solid black line is the reversed field measurements using the FBG technique taken in positive and negative fields at 25 K.