93Nb- and 27Al-NMR/NQR studies of the praseodymium based PrNb2Al20

We report a study of Nb-93- and Al-27-nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) in a praseodymium based compound PrNb2Al20. The observed NMR line at around 3 T and 30 K shows a superposition of typical powder patterns of one Nb signal and at least two Al signals. Nb-93-NMR line could be reproduced by using the previously reported NQR frequency vQ = 1.8 MHz and asymmetry parameter eta similar or equal to 0 [Kubo T et al 2014 JPS Conf. Proc. 3 012031]. From Al-27-NMR/NQR, NQR parameters are obtained to be V-Q = 1.53 MHz, and eta(A) similar or equal to 0.20 for the site A, and v(Q,B) = 2.28 MHz, and 7p3 = 0.17 for the site B. By comparing this result with the previous Al-27-NMR study of Pr T-2 (T = Ti, V) [Tokunaga Y et al 2013 Phys. Rev. B 88 085124], these two Al site are assigned to the two of three crystallographycally inequivalent Al sites.