STRUCTURAL, MAGNETIC AND ELECTRICAL PROPERTIES OF DEFICIENT LANTHANUM La0.67-x xBa0.33MnO3 PEROVSKITE MANGANITES
A. Ammar, L. Laroussi, A. Cheikh-Rouhou*
Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, B.P.802, 3018 Sfax, Tunisie
* Corresponding author. E-mail :Abdel.Cheikhrouhou@fss.rnu.tn
Received : 26 June 2001; revised version accepted :15 February 2002
Lacunar perovskite manganites La0.67-x xBa0.33MnO3 powders where is a vacancy were prepared using the classic ceramic method. X-ray diffraction patterns showed that our synthesized samples crystallize in the rhombohedral system with Rc space group for x0.05 and in the orthorhombic one with Pbnm space group for 0.10x0.20. Our samples exhibit a paramagnetic to ferromagnetic transition with decreasing temperature. Curie temperature TC evolution with deficiency content has a parabolic behavior; the maximum of TC is obtained for x0.12. Resistivity measurements show a semi-conductor to metallic transition with decreasing temperature.
Keywords: Perovskite; Manganite; Resistivity; Magnetization; Ferromagnetism.