SATURATION STUDIES ON N2 - IN IRRADIATED SODIUM AZIDE

Saturation studies of N2- in sodium azide (NaN 3) were performed at temperatures of 4.2° and 2°K and at a frequency of 9 GHz. The product T1T2 was found to be approximately 10-11 sec2. The assumption that the width of the partially resolved hyperfine structure is equal to the width of the homogeneously broadened packet allowed estimations of T2 as 10 -8 sec and T1 as 10-3 sec. This assumption, justified in the text, also allowed one to calculate an upper limit on the ratio (a) of the homogeneous to inhomogeneous linewidths of 0.07. The saturation data yielded values of 0.4-0.8 for this ratio. The spin-diffusion time, T 2l, was shown to be the order of 10-5 sec, so that spin diffusion was a dominant relaxation mechanism. This was used to explain apparent ambiguities in the values of a. The relaxation times were highly aniso tropic when the dc magnetic field was nearly parallel to the crystalline c axis. Further experiments are needed before one can understand this variation.