Transport properties in phase IV of CexLa1-xB6

We have performed the detailed studies of the magnetoresistance of CexLa1-x B6 (x = 0.75, 0.7, 0.65, 0.6, 0.5, 0.47, 0.38, 0.36, 0.25) in detail and ob tained the magnetic phase diagram of CexLa1-xB6. The results show that rece ntly discovered new phase IV exists between 0.3 less than or equal to x les s than or equal to 0.8 and the Kondo singlet ground state is realized for x < 0.3. All the long-range orders seem to disappear at x similar to 0.3. As for the nature of phase IV, judging from the results of the electrical res istivity, the specific heat, magnetic susceptibility, magnetic phase diagra m and the similarities between the natures of two phases of PrB6 and ones o f phase III and IV of Ce0.75La0.25B6, we conjecture that phase IV is the in commesurate AF magnetic oredred state.