²⁷Al-NMR/NQR spectral analysis of single crystal PrTa₂Al₂₀

We report the results and analysis of ²⁷Al nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements. NMR measurements were performed at the magnetic field parallel to <111> between 5 and 12 T. NQR measurements were performed at 4.2 K. Although the signals from the Al 16c site could not be deconvoluted, the ²⁷Al-NMR signals are assigned and electric field gradient (EFG) parameters are extracted for both the Al 48f and 96g sites. The obtained NQR parameters are ν_Q(48f) = 2.418±0.002 MHz, η(48f) = 0.175±0.005, ν_Q(96g) = 1.00±0.01 MHz, and η(96g) = 0.40±0.05. The EFG directions at the Al 48f site are determined to be V_ZZ ∥ <110> and V_XX ∥ <100>. For the Al 96g site, V_ZZ ∥ <11-bar0> and V_XX tilts by 14°±3° from <110> to <001>. (author)