Investigating the antiferromagnetic order in (001)pc SmNiO3/NdNiO3 superlattices

Rare earth nickelates (RNO3, but La) display a metal to insulator transition (MIT) as the temperature is reduced together with an unusual antiferromagnetic (AFM) order described by the (1/4,1/4,1/4)pc-wavevector below the Néel transition (TNéel). By growing superlattices (SLs) that combine SmNiO3 (SNO) and NdNiO3 (NNO) layers – two nickelates displaying different critical temperatures, we have found that TMI of the whole system is controlled by the thickness of the individual SNO and NNO layers. In this proposal, we plan to investigate the AFM order in our superlattices. We propose to perform a neutron diffraction experiment at WISH, where on one of our NNO films has been successfully measured giving us confidence that our proposed experiment is feasible. The interest lies in determining the coupling between TMI and TNéel, the mechanism of which is still under debate.