Europhys. Lett, 47 (4), pp. 487-493 (1999)
Observation of colossal positive and negative
magnetoresistance in perovskite-type
X. X. Zhang 1 and J. M. Hernandez 2
1 Department of Physics, The Hong Kong University of Science and Technology
Clear Water Bay, Kowloon, Hong Kong, China
2 Departament de Física Fonamental, Universitat de Barcelona
Diagonal 647, Barcelona 08028, Spain
(received 2 November 1998; accepted in final form 15 June 1999)
PACS. 72.15Gd - Galvanomagnetic and other magnetotransport effects.
PACS. 75.30Kz - Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.).
PACS. 71.30 - Metal-insulator transitions and other electronic transitions.
The co-existence of colossal positive and negative magnetoresistance has been observed in a perovskite-type material . The hysteretic behavior of resistivity in temperature and magnetic field suggests the existence of phase transition. Positive magnetoresistance (positive- up to 10000% was observed below insulator-metal transition temperature, , accompanied by a negative magnetoresistance (negative-MR) with further increasing magnetic field. The positive-MR may be attributed to the field-induced carrier localization (CL), whereas the very large negative-MR is believed to be due to the field-induced collapse of charge ordering.
Copyright EDP Sciences