Magnetic Properties of Nanoparticle RMnO3 (R=Pr, Nd, and Tb) Compounds

Abstract

The manganese perovskites with the general formula AMnO 3 , where A = La, a rare earth metal or Ca, Sr, etc., are subject of intensive investigations of their magnetic and electric properties. Structural and magnetic properties of these compounds are sensitive to both the manganese valence and internal (chemical) factors. The interest in the manganite has been renewed with the discovery of colossal magnetoresistance, magnetocaloric response, and multiferroic behavior. Recently, the investigations concentrate on the influence of the grain size on their properties. The model for an interpretation of the magnetic properties of the nanoparticle compounds is based on the ratio of ideal inner core and nonmagnetic surface, i.e., on the surface/volume ratio [1].For RMnO 3 (R = rare earth elements) compounds, the critical temperature of the magnetic ordering, which indicates change of magnetic interactions, decreases with increasing number of 4 f electrons (see Fig. 1 in [2]).