Ultrafast sintering of La-Ca-Mn-O bulk ceramics by thermal plasma assisted heating

Abstract

This paper reports a novel and low-cost thermal plasma assisted heating method for ultrafast sintering of rare-earth-based perovskite manganites. An indigenously designed DC thermal plasma reactor has been used to sinter La0.67Ca0.33MnO3 (LCMO) colossal magnetoresistance (CMR) material. Highly dense (96% of theoretical density) crystalline bulk LCMO ceramics were prepared within 2.5 min of sintering time. Plasma-sintered LCMO bulk ceramics showed enhanced T-C (272 K), which is close to T-IM (275 K) as compared to the conventional sintered LCMO [J. M. De Teresa, M. R. Ibarra, J. Blasco, J. Garcia, C. Marquina, P. A. Algarabel, Z. Arnold, K. Kamenev, C. Ritter, R. von Helmolt, Phys. Rev. B 54 (1996) 1187] sample. We observe that the thermal plasma heating process offers a unique advantage for quick physical densification and hence sintering within a few minutes. (c) 2007 Elsevier B. V. All rights reserved.