Abstract
We have performed the detailed studies of the magnetoresistance of CexLa1-xB6 (x=0.75, 0.7, 0.65, 0.6, 0.5, 0.47, 0.38, 0.36, 0.25) in detail and obtained the magnetic phase diagram of CexLa1-xB6. The results show that recently discovered new phase IV exists between 0.3 ≤ x ≤ 0.8 and the Kondo singlet ground state is realized for x < 0.3. All the long-range orders seem to disappear at x -- 0.3. As for the nature of phase IV, judging from the results of the electrical resistivity, the specific heat, magnetic susceptibility, magnetic phase diagram and the similarities between the natures of two phases of PrB6 and ones of phase III and IV of Ce0.75La0.25B6, we conjecture that phase IV is the incommesurate AF magnetic oredred state.
