Low-Temperature Phase Formation of Sn-Doped LaMnO3þd Perovskite

L.B. MORALES; A. CANEIRO; D. VEGA; R. ZYSLER; H. LANZA; R. C. MERCADER

JOURNAL OF SOLID STATE CHEMISTRY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2002 vol. 168 p. 100 - 109

0022-4596

The incorporation of Sn into LaMnO3 perovskite and itsinfluence on magnetotransport properties were studied insamples synthesized at low temperature. Single-phase materialsfor two series of samples with La/(Sn+Mn)=1 and La/(Sn+Mn)o1 ratios were obtained bysubstitution of up to 10%of the Mn ions bySn 4þ: The effect of Sn substitution wasmonitored through measurements of thermal, ‘‘MðTޒ’, andmagnetic field, ‘‘MðHޒ’, dependences of magnetization, as wellas of resistivity, ‘‘qðTޒ’, at 0 and 70 kOe. These showed thatthis effect depends stronglyon the perovskite cation site ratio(A/B). For La/(Sn+Mn)=1, M and TC were depressed as Sncontent was increased. The magnetization data suggest thepresence of magnetic clusters with superparamagnetic behavior.No evidence of magnetoresistance (MR) was found. For La/(Sn+Mn)o1 ratio, the samples showed ferromagnetic behaviorand MR and bothM and TC raised as Sn content increased. Theresults are discussed in terms of A site vacancies. #