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

• Published in: Journal of magnetism and magnetic materials Vol. 320; no. 8; pp. 1485 - 1489
• Main Authors: Mishra, D.K., Sahu, D.R., Singh, S.K., Mishra, P.K., Pradhan, A.K., Roul, B.K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2008; Elsevier Science
• Subjects: Colossal magnetoresistance; Condensed matter: electronic structure, electrical, magnetic, and optical properties; DC thermal plasma; Exact sciences and technology; LCMO; Magnetic properties and materials; Magnetotransport phenomena, materials for magnetotransport; Manganites; Physics; Thermal plasma heating; Thermal plasma heating; DC thermal plasma; LCMO; Densification; Sintering; Plasma assisted processing; Perovskites; Colossal magnetoresistance; Heat treatments; Manganites; Ultrafast process
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2007.12.015

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 La 0.67Ca 0.33MnO 3 (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.