NMR studies of Heusler-type intermetallic compound Mn3Si

In order to investigate the antiferromagnetic phase in Mn3Si with TN = 23 K microscopically, 55Mn NMR have been carried out in the temperature region between 2.2 and 17 K. The temperature dependences of spectrum and spin-lattice relaxation time T1 of 55Mn NMR have been measured. In the antiferromagnetic state, two different spectra corresponding to Mn(I) and Mn(II) sites are found in the resonance frequencies of 143.5 and 6.3 MHz, respectively, at 4.2 K. From these results, the internal magnetic fields on 55Mn(I) and 55Mn(II) nuclei are obtained to be 13.6 and 0.6 T, respectively. According to NMR results, a helical structure in Mn spin states is well explained compared with the transverse sinusoidal structure.