Nuclear magnetic resonance studies of CePd 2 In and LaPd 2 In at low temperatures

We report on In nuclear magnetic resonance (NMR) and nuclear quadrupolar resonance (NQR) measurements on the new heavy-electron compound CePdZIn over a wide temperature range, from 45 mK up to 30 K. CePd 2 In undergoes an antiferromagnetic (AF) phase transition at T N = 1.23 K involving small localised Ce moments of 0.11 μ B . In zero field, the spin-lattice relaxation rate T 1 −1 ( T ) shows remarkable changes in its temperature dependence. Above 3 K, T 1 −1 is constant and 850 sec −1 . Between T N and 2 T N , ( T 1 T ) −1 = 330 (Ksec) −1 , but rapidly decreases below T N . A Korringatype relaxation, characteristic for simple metals at low temperatures, with ( T 2 T ) −1 = 17(Ksec) 1 is resumed below 0.6 K. This value is an order of magnitude larger than ( T 1 T ) −1 for LaPd 2 In and therefore is associated with low-energy excitations of the itinerant charge carriers with 4 f symmetry. The T 1 −1 data at various non-zero magnetic fields fall on a single curve when plotted as a function of ( T/H ) if H exceeds 3.5 T. Thus the AF ordering, the 4 f moment fluctuations and the Kondo screening are drastically suppressed by the application of fields H of the order of 3.5 T.