Magnetism and giant magnetoresistance of HeFe6Ge6-type Y0.7Ce0.3Mn6Sn6 compound

Magnetic transitions and magnetoresistance (MR) effect of the HfFe6Ge6-type Y0.7Ce0.3Mn6Sn6 compound have been investigated in the temperature range of 5-370 K. The sample undergoes paramagnetic, ferrimagnetic, and antiferromagnetic ordering with cooling. In the antiferromagnetic state, a moderate magnetic field (less than or equal to11 kOe) is sufficient to switch Y0.7Ce0.3Mn6Sn6 from the antiferromagnetic to ferrimagnetic state, and this results in the giant magnetoresistance effect of -36.5similar to-6% from 5 K to 285 K at 50 kOe. It is found that the MR (MR=[rho(H)-rho(0)]/rho(0)x100%) behavior of the sample can be expressed as MR=-A(M/M-S)(2) in the field range from antiferromagnetic to ferrimagnetic configuration, and the power-law magnetic-field dependence of the MR effect MRproportional to-H-q is shown in the ferrimagnetic state. The values of the exponent q are 0.35, 0.46, and 0.65 at 5 K, 75 K, and 285 K, respectively. (C) 2003 American Institute of Physics.