Liquid magnetic susceptibility

The quadrupole effects mentioned in Section I.B.(l) apparently are small, as magnetic susceptibility measurements18 have revealed that the energy differences between different orientations of an oxygen molecule in a /3-hydroquinone cavity become only noticeable at liquid helium temperatures. 

Solvated electrons were first produced in liquid ammonia when Weyl (1864) dissolved sodium and potassium in it the solution has an intense blue color. Cady (1897) found the solution conducts electricity, attributed by Kraus (1908) to an electron in a solvent atmosphere. Other workers discovered solvated electrons in such polar liquids as methylamine, alcohols, and ethers (Moissan, 1889 Scott et al, 1936). Finally, Freed and Sugarman (1943) showed that in a dilute metal—ammonia solution, the magnetic susceptibility corresponds to one unpaired spin per dissolved metal atom. 

Solutions of alkali metals in liquid ammonia have been studied by many techniques. These include electrical conductivity, magnetic susceptibility, nuclear magnetic resonance (NMR), volume expansion, spectroscopy (visible and infrared), and other techniques. The data obtained indicate that the metals dissolve with ionization and that the metal ion and electron are solvated. Several simultaneous equilibria have been postulated to explain the unique properties of the solutions. These are generally represented as follows ... 

The convenient NMR observables depend on the characteristics of the system studied, but generally the protons of the liquid are readily detected. The apparent NMR linewidths are often determined by the magnetic susceptibility inhomogeneities in the sample and do not directly reflect the dynamics of the liquid. This report will focus largely on theoretical approaches to understand the spin-lattice relaxation rate constants for both classes of microporous materials. The magnetic held dependence of the spin-lattice relaxation rate constant generally provides a useful dynamical characterization of the liquid and often a structural characterization of the confining media. 

It is most important to know in this connection the compressibility of the substances concerned, at various temperatures, and in both the liquid and the crystalline state, with its dependent constants such as change of. melting-point with pressure, and effect of pressure upon solubility. Other important data are the existence of new pol3miorphic forms of substances the effect of pressure upon rigidity and its related elastic moduli the effect of pressure upon diathermancy, thermal conductivity, specific heat capacity, and magnetic susceptibility and the effect of pressure in modif dng equilibrium in homogeneous as well as heterogeneous systems. 

Silvery-white metal body-centered cubic crystals ductile soft and very hght (the fourth lightest metaUic element) Mobs hardness 0.3 density 1.522 g/cm3 at 18°C melts at 39.3°C density of the liquid metal 1.472 g/mL at 39°C vaporizes at 689°C producing a blue vapor vapor pressure 1 torr at 294°C and 10 torr at 387°C electrical resistivity 11.6 microhm-cm at 0°C and 13.1 mirohm-cm at 25°C viscosity 0.484 centipoise at 100°C magnetic susceptibility 0.09x10 cgs units at 18°C thermal neutron absorption cross section 0.73 barns reacts violently with water... 

Exists in two adotropic modifications. Crystalline sihcon is made up of grayish-black lustrous needle-hke crystals or octahedral platelets cubic structure Amorphous sdicon is a brown powder. Other physical properties are density 2.33g/cm3 at 25°C melts at 1,414°C high purity liquid silicon has density 2.533 g/cm at its melting point vaporizes at 3,265°C vapor pressure 0.76 torr at 2,067°C Mohs hardness 6.5. Brinell hardness 250 poor conductor of electricity dielectiric constant 13 critical temperature 4°C calculated critical pressure 530 atm magnetic susceptibility (containing 0.085%Fe) 0.13x10 insoluble in water dissolves in hydrofluoric acid or a mixture of hydrofluoric and nitric acids soluble in molten alkalies. 

The physical properties of solvents greatly influence the choice of solvent for a particular application. The solvent should be liquid under the temperature and pressure conditions at which it is employed. Its thermodynamic properties, such as the density and vapor pressure, temperature and pressure coefficients, as well as the heat capacity and surface tension, and transport properties, such as viscosity, diffusion coefficient, and thermal conductivity, also need to be considered. Electrical, optical, and magnetic properties, such as the dipole moment, dielectric constant, refractive index, magnetic susceptibility, and electrical conductance are relevant, too. Furthermore, molecular... 

D. L. VanderHart, Magnetic susceptibility and high resolution NMR of liquids and solids, D. M. Grant and R. K. Harris, eds., Encyclopedia of Nuclear Magnetic Resonance, Wiley, New York, 1996, 2938-2946. 

As its name suggests, a liquid crystal is a fluid (liquid) with some long-range order (crystal) and therefore has properties of both states mobility as a liquid, self-assembly, anisotropism (refractive index, electric permittivity, magnetic susceptibility, mechanical properties, depend on the direction in which they are measured) as a solid crystal. Therefore, the liquid crystalline phase is an intermediate phase between solid and liquid. In other words, macroscopically the liquid crystalline phase behaves as a liquid, but, microscopically, it resembles the solid phase. Sometimes it may be helpful to see it as an ordered liquid or a disordered solid. The liquid crystal behavior depends on the intermolecular forces, that is, if the latter are too strong or too weak the mesophase is lost. Driving forces for the formation of a mesophase are dipole-dipole, van der Waals interactions, 71—71 stacking and so on. 

The results presented in Fig. 27 represent an exciting advance because they demonstrate that the GERVAIS pulse sequence allows direct imaging of regions of liquid recirculation in both the z- and. vv-vclociiy fields. However, a word of caution is needed. Because GERVAIS is an EPI-based technique, it requires that variations in magnetic susceptibility within the sample be minimized. In this system, plastic spheres were used, which were naturally susceptibility-matched with water. If this... 

The magnetic susceptibilities of dimer liquid crystals such as NC-Ph—Ph—O—(CH2>n—Ph—Ph—CN(n 9, 10) are measured by a SQUID magnetometer. The results obtained are interpreted within the framework of the RIS approximation, the effect arising from the conformational anisotropy of the flexible spacer being strictly taken into account. The order parameters of the mesogenic core axis thus estimated are found to be consistent with those directly observed at just below 7N) by the ZH NMR technique using mesogen-deuterated samples. 

The magnetic susceptibilities of some ether-type liquid-crystalline polymers are measured by a SQUID magnetometer. The Ax values estimated for the stable nematic state are analyzed according to a known RIS scheme. 

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