HIGH MAGNETIC-FIELD STUDY OF THE SPECIFIC-HEAT OF CEB6 AND LAB6

The specific heats of CeB//6 and LaB//6 have been measured over a large range of temperatures and under magnetic fields up to 8 teslas. The data confirm that the intermediate phase of CeB//6, the so-called phase II, is favored by an applied magnetic field. Actually both the transition temperature and the associated specific heat anomaly are strongly increased by a magnetic field. To get the magnetic contribution from the CeB//6 specific heat with more accuracy, we have measured the non-magnetic compound LaB//6. The analysis of this magnetic contribution confirms that the Ce**3** plus ground state is the GAMMA //8 quartet, and the splitting with the GAMMA //7 doublet is estimated to be larger than 500 K.