Effect of mixed alkali-element substitution on structural and magnetic properties of praseodymium manganites Pr0.9(Na1-xKx)0.1MnO3

Siwar Zouari (1) , Laurent Ranno (2) , Abdelwaheb Cheikh-Rouhou (1) , Pierre Strobel (3)

1 Laboratoire de Physique des Matériaux
2 NEEL - MNM - Micro et NanoMagnétisme
3 NEEL - MRS - Matériaux, Rayonnements, Structure

The effect of cationic size mismatch at the A site at constant manganese valence on the structural and magnetic properties of a perovskite-type rare-earth manganate was investigated in the Pr0.9(Na1-xKx)0.1MnO3 solid solution system (0 ≤ x < 1). All members of this solid solution series are orthorhombic at room temperature, space group Pbnm. Structural refinements using the Rietveld method show that the cell volume increases and the static Jahn-Teller distortion decreases with increasing potassium content x. Magnetic properties are characterized by strong positive θp values, and are ascribed to a canted ferromagnetic arrangement. The high Curie constant values in the paramagnetic regime can be explained by a magnetic cluster model of 2-3 Mn ions.

Mots clés: oxides; crystal structure; magnetic properties; ferromagnetism

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Chimie inorganique

Siwar Zouari, Laurent Ranno, Abdelwaheb Cheikh-Rouhou, Pierre Strobel. Effect of mixed alkali-element substitution on structural and magnetic properties of praseodymium manganites Pr0.9(Na1-xKx)0.1MnO3. Journal of Alloys and Compounds, 2008, 452 (249), (accepté le 17/7/2007). ⟨10.1016/j.allcom.2007.07.048⟩. ⟨hal-00186049⟩