NMR line shapes and order-parameter determination in proton pseudo-spin-glasses

1988 ◽  
Vol 37 (13) ◽  
pp. 7276-7283 ◽  
Author(s):  
R. Blinc ◽  
S. Žumer ◽  
M. Koren ◽  
D. C. Ailion
Keyword(s):  
Spin Glasses ◽  
Order Parameter ◽  
Parameter Determination ◽  
Line Shapes

scholarly journals Efficient polynomial analysis of magic-angle spinning sidebands and application to order parameter determination in anisotropic samples

2021 ◽  
Vol 2 (2) ◽  
pp. 589-606
Author(s):  
Günter Hempel ◽  
Paul Sotta ◽  
Didier R. Long ◽  
Kay Saalwächter
Keyword(s):  
Chemical Shift ◽  
Magic Angle Spinning ◽  
Parameter Determination ◽  
Magic Angle ◽  
Chemical Shift Tensors ◽  
Line Shapes ◽  
Fitting Procedure ◽  
The Common ◽  
Angle Spinning

Abstract. Chemical shift tensors in 13C solid-state NMR provide valuable localized information on the chemical bonding environment in organic matter, and deviations from isotropic static-limit powder line shapes sensitively encode dynamic-averaging or orientation effects. Studies in 13C natural abundance require magic-angle spinning (MAS), where the analysis must thus focus on spinning sidebands. We propose an alternative fitting procedure for spinning sidebands based upon a polynomial expansion that is more efficient than the common numerical solution of the powder average. The approach plays out its advantages in the determination of CST (chemical-shift tensor) principal values from spinning-sideband intensities and order parameters in non-isotropic samples, which is here illustrated with the example of stretched glassy polycarbonate.

Refractive index measurements and order parameter determination of the liquid crystal p-ethoxybenzilidene-p-n-butylaniline

1981 ◽  
Vol 59 (4) ◽  
pp. 515-520 ◽  
Author(s):  
P. Palffy-Muhoray ◽  
D. A. Balzarini
Keyword(s):  
Refractive Index ◽  
Liquid Crystal ◽  
Order Parameter ◽  
Orientational Order ◽  
Parameter Determination ◽  
Refractive Indices ◽  
Temperature Changes ◽  
Interferometric Technique ◽  
Anisotropic Fluids

Using a simple new interferometric technique, the ordinary and extraordinary refractive indices of the nematic liquid crystal p-ethoxybenzilidene-p-n-butylaniline have been measured separately as a function of temperature. Changes in the refractive indices have been measured with an accuracy of ±0.005% and the absolute values with an accuracy of ±0.5%. Thermal expansivity data has been obtained by utilizing a specially constructed thermometer containing the sample. By using a recently developed Clausius–Mossotti relation for anisotropic fluids, the effective molecular polarizability and hence the orientational order parameter have been obtained from refractive index and density measurements as a function of temperature.

scholarly journals Spin-label Order Parameter Calibrations for Slow Motion

2017 ◽  
Vol 49 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Derek Marsh
Keyword(s):  
Order Parameter ◽  
Hyperfine Coupling ◽  
Rotational Diffusion ◽  
Slow Motion ◽  
Molecular Axis ◽  
Spin Labels ◽  
Paramagnetic Resonance ◽  
Line Shapes ◽  
Orientation Order ◽  
Isotropic Hyperfine Coupling

Abstract Calibrations are given to extract orientation order parameters from pseudo-powder electron paramagnetic resonance line shapes of 14N-nitroxide spin labels undergoing slow rotational diffusion. The nitroxide z-axis is assumed parallel to the long molecular axis. Stochastic-Liouville simulations of slow-motion 9.4-GHz spectra for molecular ordering with a Maier–Saupe orientation potential reveal a linear dependence of the splittings, $$2A_{\hbox{max} }$$ 2 A max and $$2A_{\hbox{min} }$$ 2 A min , of the outer and inner peaks on order parameter $$S_{zz}$$ S z z that depends on the diffusion coefficient $$D_{{{\text{R}} \bot }}$$ D R ⊥ which characterizes fluctuations of the long molecular axis. This results in empirical expressions for order parameter and isotropic hyperfine coupling: $$S_{zz} = s_{1} \times \left( {A_{\hbox{max} } - A_{\hbox{min} } } \right) - s_{o}$$ S z z = s 1 × A max - A min - s o and $$a_{o}^{{}} = \tfrac{1}{3}\left( {f_{\hbox{max} } A_{\hbox{max} } + f_{\hbox{min} } A_{\hbox{min} } } \right) + \delta a_{o}$$ a o = 1 3 f max A max + f min A min + δ a o , respectively. Values of the calibration constants $$s_{1}$$ s 1 , $$s_{\text{o}}$$ s o , $$f_{\hbox{max} }$$ f max , $$f_{\hbox{min} }$$ f min and $$\delta a_{o}$$ δ a o are given for different values of $$D_{{{\text{R}} \bot }}$$ D R ⊥ in fast and slow motional regimes. The calibrations are relatively insensitive to anisotropy of rotational diffusion $$(D_{{{\text{R}}//}} \ge D_{{{\text{R}} \bot }} )$$ ( D R / / ≥ D R ⊥ ) , and corrections are less significant for the isotropic hyperfine coupling than for the order parameter.

scholarly journals Long-range Order Parameter Determination by Convergent Beam Electron Diffraction

2010 ◽  
Vol 16 (S2) ◽  
pp. 250-251
Author(s):  
KL Torres ◽  
RR Vanfleet ◽  
GB Thompson
Keyword(s):  
Electron Diffraction ◽  
Long Range ◽  
Order Parameter ◽  
Convergent Beam Electron Diffraction ◽  
Range Order ◽  
Parameter Determination ◽  
Range Order Parameter ◽  
Long Range Order ◽  
Beam Electron ◽  
Convergent Beam

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Raman scattering line shapes as a probe of the order parameter symmetry in high — Tc superconductors

1994 ◽  
Vol 235-240 ◽  
pp. 1077-1078
Author(s):  
K.P. Jain ◽  
A.K. Shukla ◽  
R. Ramakumar ◽  
Ratnamala Chatterji ◽  
M. Fukutomi
Keyword(s):  
Raman Scattering ◽  
Order Parameter ◽  
High Tc Superconductors ◽  
High Tc ◽  
Line Shapes ◽  
Parameter Symmetry ◽  
Order Parameter Symmetry
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