C-13 AND N-15 NMR IN THORIUM CARBIDES AND CARBONITRIDES

Knight-shifts and spin-lattice relaxation times were measured on **1**3C and **1**5N in Th**1**3C//0//. //7//5, Th**1**3C, Th**1**3C//0//. //6**1**5N//0//. //4, Th**1**5N. Large enhancements of the Korringa constant, of the order of ten times the free electron value, are found. The measured spin-lattice relaxation times and Knight-shifts contain strong orbital paramagnetic contributions especially in the case of Th**1**3C. These results are consistent with the lack of metalloid 2s electrons at the Fermi level, in agreement with band calculations. A minimum of density of states at the Fermi level is found for ThC//0//. //6N//0//. //4. The **1**3C N. M. R. properties do not vary from ThC to ThC//0//. //7//5, showing that the observed increase of electronic specific heat must be attributed to the 6d thorium band states.