Sr 2Mn 2O 5 magnetic structure

Abstract

The nuclear and magnetic structures of the oxygen deficient perovskite Sr 2Mn 2O 5 have been investigated by neutron powder diffraction. This compound crystallizes in orthorhombic space group Pbam with a ≈ √2 a p, b ≈ 2√2 a p and c ≈ a p (with a p ≈ 3.84 A ̊ ), and exhibits antiferromagnetic order below 380 K. The resolution of the magnetic structure at room temperature and 4.2 K shows that the Mn +3 ions (d 4) order with a propagation vector k = (0,0,1/2) and a magnetic moment of 3.2 μ B at 4.2 K. Each manganese is in square pyramidal coordination, and is coupled antiferromagnetically with three neighbours and ferromagnetically with two others.