Heat capacity measured up to 60 T in Ce3Bi4Pt3 Kondo insulator

The low-temperature heat capacity C(T) of the Kondo insulator Ce3Bi4Pt3 has been measured in the new 60 T long pulse magnet at NHMFL-LANL. A large inc rease in the zero temperature Sommerfeld coefficient gamma = (C/T)(T-->0) i s observed in a magnetic field of 40 T. The high magnetic field value gamma (40T) = 47 mJ/mol K-2 is consistent with a magnetic held induced Kondo insu lator to heavy fermion metal phase transition, observed for the first time with a thermodynamic probe. (C) 2000 Published by Elsevier Science B.V. All rights reserved.