NMR lineshapes in solid hydrogen through the phase transition

We have performed NMR measurements and obtained lineshapes in solid hydrogen using the free-induction decay(FID) and the echo sequences. The temperature range investigated included the long range orientationally ordered phase transition. Away from the phase transision, the lineshapes from the echo sequences approximated the true lineshape from the FID reasonably well. However there was a considerable deviation near the transition temperature. Details of these experimental results are discussed. (Author)