Lattice magnetization

Minerals normally considered nonmagnetic may be rendered magnetic by elemental substitution of a small amount of a magnetic element in the crystal lattice. Magnetic properties may also be affected by partial alteration in weathering effects. 

To summarize, the analysis of dynamical properties have shown that the H0B22C2N system is not a simple superparamagnet, nor a typical 3D spin glass, but a new 2 dimensional spin glass system (Mori and Mamiya, 2003). In fact, a dilute triangular lattice magnetic system. 

Keywords Anderson model, Kondo lattice, magnetic susceptibility, strong correlation. 

Spectygscopic techniques such as fluorescence anisotropy decay (FAD), and C spin-lattice magnetic relaxation (T NMR) are well suited to investigation of the local dynamics of polymer melts. 

Spin-lattice magnetic relaxation times T. on nuclei were measured at 25.15 MHz and 62.5 MHz using Jeol PS 100 and Bruker WP 250 spectrometers respectively. DMS0-d6 was used as an external lock. Tj was obtained from the 180 -t-90 sequence with an accuracy of 1 7,. 

The local dynamics of polymer chains can be studied by C NMR through measurements of J e spin-lattice magnetic relaxation time, T. The spin of a given relaxes by dipolar relaxation... 

In this paper we have investigated the segmental motions of bulk polybutadiene, in a temperature range hig r than (Tg + 60K), by using fluorescence anisotropy decay, and C spin-lattice magnetic relaxation time, Tp... 

Exchange interactions in heterodinuclear transition metal complexes have attracted the attention of many researchers in the last few years. Nickel(II)-copper(II) dimers are, in a sense, the simplest systems to be investigated and several complexes containing paramagnetic nickel(II) and copper(II) ions have been reported, as pure complexes or as impurities in a parent lattice. " Magnetic susceptibility or EPR spectroscopy has been used to... 

The heat capacity measurements of Lounasmaa (1962a) (0.4. 0 K) were analyzed in terms of nuclear, electronic, and combined lattice-magnetic terms. Further to these measurements, a number of new determinations have helped to improve the fit. The measurements of Lounasmaa and Sundstrom (1967) showed that the discrepant Run III of Lounasmaa (1962a) was incorrect and therefore rejected. Rosen (1967) determined the Debye temperature from elastic constant measurements to be 169 K at 4.2 K, equivalent to a lattice contribution to the heat capacity as 0.403 mJ/(mol K" ). With the values of the nuclear and lattice contributions fixed, the heat capacity values of Lounasmaa (1962a) were used to derive the electronic... 

Fig. 7. Variation of the sub-lattice magnetization in the antiferromagnet GdV04 below = 2.4955(5)K. O from NMR frequency of V (J=i) (Bleaney et al. 1981c). Mossbauer data (Cook and Cashion 1979). — Molecular field theory.

Fig. 5.2. The heat capacity of jS-Ce showing the electronic, lattice, magnetic and Schottky contributions (private communication from K.A. Gschneidner, Jr.).

The specific heat at low temperatures consists of electronic, lattice, magnetic, and hyperfine contributions (see for example, Junod 1996). The electronic contribution in a metal due to the conduction elections is linear in temperature. In a BCS superconductor, the conduction electrons start to condense into Cooper pairs at and the density of unpaired electrons decreases exponentially below this temperature. Hence, at the temperatures of interest in this chapter (i.e., below 4K) the density of unpaired electrons is essentially zero as is expected for the electronic contribution. However, for RBa2Cu30j (R123x) a linear term of the order of y = 3-6 mJ mole was always observed (van der... 

Chapter 200, by Peter M. Allenspach and M. Brian Maple, reviews some aspects of the low-temperature heat capacity of the ceramic oxide superconductors. These measurements yield valuable information about the electronic, lattice, magnetic, crystalline electric field and hyperfine nature of the various rare-earth cuprate materials, and in that respect compliment other physical property studies, such as neutron diffraction, inelastic neutron scattering, and various spectroscopic measurements. The authors review the heat-capacity properties of the stoichiometric RBaCu307 compoimds and oxygen-deficient materials, and show that there are significant differences. The heat capacities of other lanthanide cuprates, such as RBa2Cu40g and R2B4CU7O14+X, are also discussed. 

The system of equations for sub-lattices magnetizations Eq. (3.4) is essentially simplified if one chooses the concrete type of ordering. 

As it can be seen fixrm Figure 1.2, the following correlations between sub-lattices magnetizations take place in this case... 

For all three collinear antiferromagnetic structures C and G the temperature dependence of separate sub-lattice magnetization near ordering temperature has the form... 

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