SMALL-CLUSTER CALCULATIONS OF THE LOCALIZED-MOMENT CONTRIBUTION TO THE SPECIFIC-HEAT OF HEAVILY-DOPED SI-P

The localized-moment contribution to the specific heat of Si:P in the vicinity of the metal-insulator transition has been calculated as a fu nction of temperature and magnetic field. The magnetic susceptibility has also been obtained and compared with available experimental data. Small clusters of spins are used in the calculations. The specific-hea t predictions are in fairly good agreement with experimental data in f ields up to 5.7 T for n /n(c) < 0.2. At higher concentrations a reduce d number of effective spins must be used in order to obtain reasonable agreement with experiment.