Second Order Nuclear Quadrupole Effects in Single Crystals: Part II. Experimental Results for Spodumene

Experiments on the splitting of the Al27 resonance absorption line in a single crystal of LiAl(SiO3)2 (spodumene) are described, and are used to illustrate the second order theory of Part I. for Al27 nuclei in spodumene is found to be 2950 ± 20 kc./sec. at Al sites is found to be 0.94 ± 0.01. The x principal axis (corresponding to the smallest eigenvalue ) of at the Al sites is found to coincide with the b axis of the monoclinic spodumene crystal. The other two principal axes lie in the ac plane with the y axis (corresponding to the intermediate eigenvalue ) making an angle of with the crystal c axis towards the a axis. The y principal axis at the Al sites and the z principal axis at the Li sites appear to point at the projection of the nearest oxygen ion in each case. The new method of spin determination proposed in Part I is checked by confirming the known value I = 5/2 for Al27.