Nuclear Magnetic Resonance of Ferromagnetic Mn3AlC and Mn3GaC

The nuclear magnetic resonances in metallic perovskite compounds Mn 3 AlC and Mn 3 GaC have been studied. In Mn 3 AlC the Al 27 and Mn 55 resonances are observed at 78 and 140 MHz, respective at 4.2 K. The corresponding hyperfine fields at Mn 55 and Al 27 and 133 and 70 kOe at 0 K, respectively. In Mn 3 GaC three signals are observed only in the ferromagnetic phase. The resonances occur at 120, 156.5 and 199 MHz at 136 K, which are assigned to Mn 55 , Ga 69 and Ga 71 nuclei, respectively. The hyperfine fields at Mn 55 and Ga nuclei are 123 and 163 kOe at 0 K respectively. The temperature dependence of the frequencies and the echo intensity have been measured.