La0.7Ca0.3Mn0.95M0.05O3 manganites (M = Al, Ga, Fe, Mn, and In) : Local structure and electron configuration effect on Curie temperature and magnetization

• Published in: Physica. B, Condensed matter Condensed matter, 2007-01, Vol.388 (1-2), p.16-19
• Main Authors: ULYANOV, A. N, KIM, J. S, SHIN, G. M, SONG, K. J, KANG, Y. M, YOO, S. I
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Magnetotransport phenomena, materials for magnetotransport; Manganites; Physics
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2006.04.033

X-ray diffraction and magnetization measurements have been carried out in La0.7Ca0.3Mn0.95M0.05O3 manganites (M=Al, Ga, Fe, Mn, and In). It was found that the samples belong to orthorhombic phase and lattice parameters increase with increasing ionic radius of the dopants. Curie temperature, TC, changes with doping due to a difference between the electron configuration (E-factor) and ionic radius (S-factor) of the dopants and manganese trivalent ion. The E-factor affects the TC stronger than the S-factor and causes the TC decrease. The S-factor can cause both positive and negative change in DeltaTC. The DeltaTC change, caused by the S-factor, is positive if ionic radius of the dopant is less than that of Mn3+ ion, and negative in opposite case, if dopant ionic radius is larger than that of Mn3+ ion. Saturation magnetization of the manganites decreases continuously with increasing ionic radius of the substituents and almost independent of magnetic nature of the dopants.