Synthesis and characterisation of Sr1.2Nd0.8Mn0.6Rh0.4O4

Abstract

A polycrystalline sample of Sr_1.2Nd_0.8Mn_0.6Rh_0.4O₄ has been synthesised and characterised by neutron diffraction, dc magnetometry, muon spectroscopy and magnetotransport measurements. It is an n = 1 member of the Ruddlesden–Popper (RP) A_n + 1B_nO_3n + 1 family, having tetragonal (I4/mmm) symmetry [a = 3.86418(6), c = 12.4414(2) Å]. Rh and Mn cations are disordered over the six-coordinate sites within the perovskite layers of the RP structure and the A sites are occupied by a disordered distribution of Nd and Sr. In contrast to the analogous compound Sr_1.2La_0.8Mn_0.6Rh_0.4O₄, which showed long range ferromagnetic ordering in an applied field at 2 K, a spin-glass transition was observed at 16 K for the Nd-containing compound. No long range magnetic order was observed at 2 K. A maximum magnetoresistance of ∼30% in a 140 kOe field was found at 125 K.