COLOSSAL MAGNETORESISTANCE OF 1,000,000-FOLD MAGNITUDE ACHIEVED IN THE ANTIFERROMAGNETIC PHASE OF LA1-XCAXMNO3

Record values of colossal magnetoresistance (CMR) have been achieved in the antiferromagnetic phase of the La1-xCaxMnO3 system. At 125 K, the CMR of the La0.5Ca0.5MnO3 reaches nearly 1 000 000%. It increases exponentially to 100 000 000% at 57 K. While the ground state is primarily an antiferromagnet, application of a magnetic field induces a ferromagnetic alignment of spins that is highly beneficial to the electron conduction. Other ferromagnetic samples exhibit very sharp magnetic phase transitions, with which the magnetotransport is closely correlated. (C) 1995 American Institute of Physics.