Dilatometric study of spontaneous magnetostriction in NdMg antiferromagnet

We present dilatometric measurements of spontaneous magnetostriction in NdMg cubic antiferromagnet. This compound displays two spontaneous antiferromagnetic phases, both of which reduce the point symmetry to tetragonal, dividing the sample into three types of magnetostriction domains. However, applying a magnetic field along the appropriate direction for domain selection, we could extract the spontaneous magnetostriction. The results are in perfect agreement with x-ray data, with the benefit of a higher accuracy and a wider temperature range.