Europhys. Lett.
Volume 47, Number 4, August 1999
Page(s) 487 - 493
Section Condensed matter: electronic structure, electrical, magnetic and optical properties
Published online 01 September 2002
DOI: 10.1209/epl/i1999-00414-0

Europhys. Lett, 47 (4), pp. 487-493 (1999)

Observation of colossal positive and negative magnetoresistance in perovskite-type manganese oxide ${\rm Nd}_{0.67}{\rm Ca}_{0.33}{\rm MnO}_{3}$

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${\rm +h}$ - Metal-insulator transitions and other electronic transitions.


The co-existence of colossal positive and negative magnetoresistance has been observed in a perovskite-type material ${\rm Nd}_{0.67}{\rm Ca}_{0.33}{\rm MnO}_{3}$. The hysteretic behavior of resistivity in temperature and magnetic field suggests the existence of phase transition. Positive magnetoresistance (positive-${\rm MR}=[\rho(B)-\rho(0)]/\rho(0))$ up to 10000% was observed below insulator-metal transition temperature, $T_{\rm I\mbox{-}M} \sim 45\;{\rm K}$, 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.


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