Abstract
Detailed 27Al and 63Cu nuclear magnetic resonance (NMR) experiments have been performed in between 4.5 and 295 K on a polycrystalline sample of CeCu 3Al 2 which has a Kondo temperature ∼ 11 K . The NMR spectral features and Knight shift measurements show that in this compound, Cu occupy both c and g lattice sites, while Al occupy only the g sites. From the temperature dependence of Knight shift ( K), the hyperfine fields for 63Cu and 27Al at the g sites have been estimated as 2.02(5) and 1.67 ( 5 ) kOe / μ B , respectively, and that for 63Cu at c sites as − 3.83 ( 5 ) kOe / μ B . Nuclear spin-lattice relaxation time ( T 1) measurements indicate that though the relaxation process is governed by fluctuations of magnetic interaction, nuclear quadrupolar interaction also has a significant contribution, especially towards relaxation of 63Cu in both c and g sites. For 27Al, K and T 1 have yielded the effective 4f-spin correlation rate 1 / τ 4 f . The behavior of its temperature dependence indicates that at low temperatures in CeCu 3Al 2, the valence state of cerium might not be stable.
Published Version
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