Magnetotransport Behavior And The Phase Diagram Of Nd1-Xcaxmno3 Manganites

In this work, the temperature dependent magnetization M(T) and the electrical resistivity rho(T) of Nd1-xCaxMnO3 (x = 0.1-0.5) are measured. From the M(T) curves, the ferromagnetic (FM) phase is observed for samples of x = 0.1 and 0.2. However, the canted-antiferromagnetic (CAF) phase which coexists with the charge-ordering (CO) phase occurs at low temperature for samples x = 0.3-0.5. By systematically changing the Ca concentration from x = 0.1 to 0.5, a detailed phase diagram is established. Based on the result of magnetic field dependent rho(T), the magnetoresistance ratio is calculated, which shows a maximum in the x = 0.4 sample. These results are helpful for improving the MR effect in these manganites.