Eur. Phys. J. B 60, 273-279 (2007)
https://doi.org/10.1140/epjb/e2007-00349-2

High resolution diffraction and small angle scattering neutron investigations of LaCo_0.5Mn_0.5O_3+δ: effect of oxygen content

¹ Institute of Solid State and Semiconductor Physics, National Academy of Sciences, Brovki str. 19, Minsk, 220072, Belarus
² M.V. Lomonosov Moscow State University, 119899 Moscow, Russia
³ Berlin Neutron Scattering Center, Hahn-Meitner-Institute, Glienicker str. 100, 14109 Berlin, Germany

Corresponding author: ^a karpinsky@ifttp.bas-net.by

Received: 5 February 2007
Published online: 22 December 2007

Abstract

We have investigated LaCo_0.5Mn_0.5O_3+δ compounds with different oxygen content by means of magnetization, high resolution and small-angle neutron diffraction measurements. Oxygen content decrease down to stoichiometric composition leads to an essential increase of T_C and magnetic moment while Co/Mn ionic ordering degree is kept almost constant. It is assumed that upon oxygen reduction Co³⁺ ions change their valence state down to 2+ one that leads to dominating of Co²⁺-Mn⁴⁺ ferromagnetic interactions as well as T_C increase. Magnetic properties can be explained in terms of coexistence of long-range ferromagnetic order and short-range clusters with antiferromagnetic interactions prevailing. Size distribution of the mentioned short-range magnetic inhomogeneities is rather mild within the samples but it is strongly temperature dependent.