Under the terms of the Creative Commons Attribution (CC BY) license to their work.The magnetic properties of layered-perovskite RbMnF4 have been investigated by neutron powder diffraction. This compound exhibits a magnetic ordering below Tc=3.7±0.2 K. The resolution of the magnetic structure at 1.5 K indicates that RbMnF4 orders as a collinear antiferromagnet. The propagation vector is k=0 and the magnetic moment of each sublattice has a value of 2.97(3) μB. The strong reduction of the observed magnetic moment should be attributed to a particularly high two-dimensional character of this compound.The research in Zaragoza has been supported by Grant No. MAT/91-681, from the Comision Interministerial deCiencia y Tecnologia.Peer Reviewe
