Magnetic and electronic nature of layered manganese oxysulfide Sr 2CuMnO 3S

Abstract

We have synthesized and investigated the magnetic and electronic nature of layered manganese oxysulfide Sr 2CuMnO 3S which crystallizes in an unusual intergrowth structure with Cu 2S 2 and pyramidal MnO 5 layers separated by Sr ions. A Cu 2p x-ray photoemission spectroscopy (XPS) spectrum of Sr 2CuMnO 3S indicates that the Cu ion is in the monovalent state, or Cu +. This feature of the Mn 2p XPS spectrum of Sr 2CuMnO 3S is similar to that of the parent compound La 3+Mn 3+O 3 of colossal magnetoresistance materials. The MnO 5 cluster model analysis suggests that the electronic nature of the pyramidal MnO 5 layers belongs to a strongly correlated electron system, and the system is the so-called Mott insulator resulting from the strongly correlated electron nature. Magnetic susceptibility (χ) exhibits low-dimensional antiferromagnetic ordering of Mn 3+ in pyramidal MnO 5 layers. Fitting the χ data to Curie-Weiss law provides evidence of strong second neighbor Mn-Mn interaction. © 2002 American Institute of Physics.