Larmor frequency spin-lattice relaxation profiles in nematic nPCH: an anomalous behavior

R. H. ACOSTA; D. J. PUSIOL

Lisboa, Portugal

Congreso; 30th ISMAR International conference on Magnetic Resonance & Related Phenomena; 2000

Experimental T1-profiles of n-cyano- phenylcyclohexane (3,4,7-PCH) at 310C (Figure1) were recorded by means of aconventional (5*106<nL<108Hz) and fast field cycling(103<nL<106 Hz) NMR spectrometers. With both instrumentsthe random error of the individual T1 points is less than 10%after appropriate signal averaging, and the sample temperaturehas been controlled with an accuracy of at least 0.2oC. TheFFC experimental set-up is home made [7], the design isbased on a electronically switched FFC-NMR spectrometerwhich uses a special air core magnet design and a MOSFETsmagnet control and power switching [8]. Additional coils areused for shimming the detection magnetic field. The earth’sfield is compensated