Development of Short-range Correlations of 4f Electrons in the Non-Kramers Γ₃ System PrNb₂Al₂₀ at Low Temperatures Investigated by NMR Measurements

Abstract

We report the results and analysis of 27 Al and 93 Nb nuclear magnetic resonance (NMR) measurements in PrNb 2 Al 20 below ~5 K at ~3 T. The NMR signal intensity reduces with decreasing temperature. In the same temperature range, the 93 Nb spin-echo decay rate 93 T 2 −1 is remarkably enhanced compared with the previous nuclear quadrupole resonance (NQR) study. Such enhancement of the spin-echo decay is also observed in the spin-glass system and cuprates reflecting the development of the short-range correlation of spins. The origin of the enhanced spin-echo decay behaviors in the NMR case is discussed. The experimental result suggests the short-range correlation of multipoles develops at low temperatures in PrNb 2 Al 20 .