Exploring piezomagnetism in Mn3NiN thin films

The family of manganese antiperovskites with the formula Mn3+xT1-xN (T = Sn, Ni, Ga..) have recently attracted much attention due to the range of interesting properties they display, such as barocaloric, Invar and piezomagnetic (PME) effects. The interplay of magnetic and elastic properties and the constraints due to the geometric frustration of the non-collinear antiferromagnetic structure underlies these phenomena. Recently we have predicted giant PME in antiperovskite films. We have successfully grown films of Mn3NiN on various substrates, which are strained compared to the bulk and show a magnetic signature. Using POLREF, we propose to study the magnetisation as a function of depth in strained 30nm and 50nm thick Mn3NiN thin films on MgO substrates, to determine how the magnetisation is distributed through the film and the role played by the strain induced by the substrate.