Nowak B, Troć R
W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wrocław.
Solid State Nucl Magn Reson. 2000;18(1-4):53-8. doi: 10.1006/snmr.2000.0010.
The ternary compound UNiAl exhibiting an antiferromagnetic order below T(N) = 19.3 K has been studied in the paramagnetic state using the 27Al NMR technique and different magnetically oriented samples. The quadrupole coupling constant e2qQ/h = 1.56 MHz is temperature independent. The dominant, longitudinal component of the Knight shift with respect to the hexagonal c axis, Kparallel, is positive and increases upon lowering the temperature down to 50 K. Much smaller in magnitude, the transverse component, Kperpendicular, is also positive and only slightly temperature dependent. The plots of the Knight shift vs magnetic susceptibility Kparallel(chi parallel) and Kperpendicular (chi perpendicular) form the same line, which implies that the transferred hyperfine field of 9.2 kOe/microB for 27Al nuclei should be considered isotropic.