Journal of Magnetism and Magnetic Materials 246 (2002) 10–15 Structure and magnetotransport properties in plasma-sprayed La 0.78 Sr 0.22 MnO 3 thick film M.T.D. Orlando a, *, A.G. Cunha a , J.C.C. Freitas a , C.G.P. Orlando a , S. Bud’ko b,1 , B. Giordanengo b , I.M. Sato c , L.G. Martinez c , E.M. Baggio-Saitovitch b a Centro de Ciencias Exatas, Departamento de F! ısica, Universidade Federal do Esp ! ırito Santo, Av Fernando Ferrari S/N, Vit ! oria, ES 29060-900, Brazil b Centro Brasileiro de Pesquisas F! ısicas, Rua Dr. Xavier Sigaud 150, Rio de Janeiro 22290-180, Brazil c Instituto de Pesquisas Energ ! eticas e Nucleares, Travessa R 400, USP, S * ao Paulo 05508-900, Brazil Received 25 June 2001; received in revised form 29 October 2001 Abstract Thick films of La 0.78 Sr 0.22 MnO 3 were produced by the plasma-spray technique onto stainless-steel substrate at 9301C. These films were obtained without the use of bond-layer, buffer-layer and annealing after deposition. The compound was deposited by a plasma-spray torch using nitrogen as the working gas. The films with thickness varying from 20 to 60 mm have good adherence and are composed of large splats with high degree of interconnection and small number of defects, as revealed by scanning electron microscopy. X-ray diffractometry analysis of the as-deposited film revealed that it had the same crystal structure as the original bulk. Measurements of electrical resistivity versus temperature for the film revealed a magnetic transition temperature near 340 K, with a ferromagnetic/metallic behavior below this temperature. The magnetoresistance of La 0.78 Sr 0.22 MnO 3 films exhibited similar magnetic field dependence as compared to the bulk sample, which indicates that the plasma-spray technique can be successfully employed for the deposition of thick films of manganites on large-area substrates while maintaining the main bulk properties. r 2002 Published by Elsevier Science B.V. PACS: 75.30.Vn; 52.75.Rx Keywords: Manganites; Plasma-spray; Thick films; Magnetoresistance 1. Introduction The perovskite-type manganites RE 1x AE x M- MnO 3 (RE=rare earth or Y, AE=alkaline earth) have been extensively studied in recent years due to their intriguing electrical and magnetic proper- ties. These materials present a remarkably large negative magnetoresistance (commonly referred to as colossal magnetoresistance (CMR)) near the Curie temperature T C ; which places them as promising candidates for applications in magnetic recording devices (for a recent review on CMR in manganites see Refs. [1,2]). The La 1x Sr x MnO 3 compounds exhibit a ferromagnetic metallic (FM) state for x in the range from 0.16 up to about 0.5. T C increases steeply with x up to the value *Corresponding author. Fax: +55-27-33352823. E-mail address: orlando@cce.ufes.br (M.T.D. Orlando). 1 Current address. Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA. 0304-8853/02/$ - see front matter r 2002 Published by Elsevier Science B.V. PII:S0304-8853(01)00953-2