Electrical resistivity, magnetic susceptibility and specific heat were measured for Yb4As2.7P0.3 between 4.2 and 300 K. The value of γ increased more than twice as large as that in the case of Yb4As3 while the number of Yb3+ increased only 4%. Characteristics of heavy fermion of extremely low carrier concentration were more enhanced.
Magnetic and transport properties in Yb4As2.7P0.3