In-NQR study of CeIn3 under pressure

In order to investigate the evolution of magnetic properties when the groun d state changes from magnetism to superconductivity, we have performed In-N QR measurements under hydrostatic pressure in heavy-fermion antiferromagnet ic compound, CeIn3. Peaks in the In-NQR spectra were shifted in the magneti cally ordered state due to the appearance of the asymmetric parameter eta, which enables us to determine the ordering temperature T-N, precisely. T-N in our measurement is in good agreement with that from the resistivity meas urement. Nuclear spin-lattice relaxation rate 1/T-1 increases gradually upo n cooling in the paramagnetic state at pressure (P) smaller than 15 kbar, w hereas 1/T-1 shows slightly decreasing behavior with decreasing T above T-N at P > 15 kbar. It is suggested that the magnetic property at T-N may chan ge from the localized to itinerant regime around 15 kbar, above which the K ondo temperature T-K is higher than T-N. (C) 2000 Elsevier Science B.V. All rights reserved.