A. Kaikkonen et al., 5 QUANTUM COHERENCE OF I=5 2 NUCLEI - AL-27 IN POLYCRYSTALLINE ALCL3/, Solid state nuclear magnetic resonance, 10(3), 1998, pp. 129-135
Optimal conditions were calculated for the excitation and detection of
the five quantum coherence of quadrupolar nuclei with 1 = 5/2 in powd
er samples, observed by the two-pulse sequence (theta(1))(x) - tau(1)
- (theta(2))(alpha) -tau(2), where alpha is the phase cycling angle. W
e varied the pulse lengths and the relative values of the nutation fre
quency omega(1) = gamma B-1 and the quadrupolar frequency omega(Q). Al
so, the effect of the resonance offset was studied under optimal condi
tions. Besides, the conditions for obtaining the maximal echo amplitud
e after the two-pulse sequence with alpha=y were found. Theoretical re
sults were compared with experiments on Al-27 nuclei in polycrystallin
e AlCl3. (C) 1998 Elsevier Science B.V.