CHARACTERIZATION OF ORDER FLUCTUATIONS IN LIQUID-CRYSTALS BY THE DIPOLAR-CORRELATION EFFECT OF THE STIMULATED ECHO

被引:33
作者
GRINBERG, F
KIMMICH, R
机构
[1] Universität Ulm, Sektion Kernresonanzspektroskopie
关键词
D O I
10.1063/1.469603
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
ANMR method is presented which permits one to probe order fluctuations in ordered materials such as nematics. Information on the order parameter is also accessible. The principle is based on the standard stimulated-echo three-pulse sequence. Both the stimulated and the primary echo are recorded. The quotient of the echo amplitudes is measured as a function of the spacing of the first two rf pulses. The attenuation curves of the quotient corrected for spin-lattice relaxation show strong modulations directly reflecting the order parameter of the material. This dipolar-correlation effect moreover provides information on the distribution of the director fluctuation modes. The time scale exceeds the millisecond range by far. A formalism has been developed which permits us the quantitative description of experimental data measured in nematic 5CB. © 1995 American Institute of Physics.
引用
收藏
页码:365 / 370
页数:6
相关论文
共 11 条
[1]   EXCHANGE NARROWING IN PARAMAGNETIC RESONANCE [J].
ANDERSON, PW ;
WEISS, PR .
REVIEWS OF MODERN PHYSICS, 1953, 25 (01) :269-276
[2]  
DONG RY, 1994, NUCLEAR MAGNETIC RES
[3]   SPIN ECHOES [J].
HAHN, EL .
PHYSICAL REVIEW, 1950, 80 (04) :580-594
[4]   NUCLEAR MAGNETIC RESONANCE IN SOLIDS - THERMODYNAMIC EFFECTS OF A PAIR OF RF PULSES [J].
JEENER, J ;
BROEKAER.P .
PHYSICAL REVIEW, 1967, 157 (02) :232-&
[5]   ONE-DIMENSIONAL AND 2-DIMENSIONAL PULSE SEQUENCES FOR DIFFUSION EXPERIMENTS IN THE FRINGE-FIELD OF SUPERCONDUCTING MAGNETS [J].
KIMMICH, R ;
FISCHER, E .
JOURNAL OF MAGNETIC RESONANCE SERIES A, 1994, 106 (02) :229-235
[6]  
KIMMICH R, UNPUB
[7]   NMR FIELD-CYCLING STUDY OF PROTON AND DEUTERON SPIN RELAXATION IN THE NEMATIC LIQUID-CRYSTAL 4-N-PENTYL-4'-CYANOBIPHENYL [J].
KOLLNER, R ;
SCHWEIKERT, KH ;
NOACK, F ;
ZIMMERMANN, H .
LIQUID CRYSTALS, 1993, 13 (04) :483-498
[9]   NUCLEAR RELAXATION IN A NEMATIC LIQUID CRYSTAL [J].
PINCUS, P .
SOLID STATE COMMUNICATIONS, 1969, 7 (04) :415-&
[10]   FREQUENCY-DEPENDENCE OF PROTON SPIN RELAXATION IN LIQUID-CRYSTALLINE PAA [J].
WOLFEL, W ;
NOACK, F ;
STOHRER, M .
ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES, 1975, A 30 (04) :437-441