No abstract

Effective thermal conductivity of binary dispersed composites over wide ranges of volume fraction, temperature, and pressure System employing laser heating for the measurement of hightemperature properties of materials over a wide pressure range Rev. Sci. Instrum. 48, 632 (1977); 10.1063/1.1135096Compact, magnetic recirculating pump for widerange temperature and pressure operation Rev.

By methods described by Gerkin and Rogers [J. Chem. Phys. 66, 4166 (1977)], high precision values of the spin-Hamiltonian parameters b20, b40, and b60, and of the zero-field splittings, for Gd3+ dilutely substituted in single crystals of 13 lanthanide ethyl sulfate nonahydrates at room temperature (24.130° C) are presented. Since sample shape dependence is significant at the reported level of precision, the measured values were adjusted to yield corresponding values for spherical samples via the analysis of shape dependence presented by Gerkin and Rogers [J. Chem. Phys. 68, 504 (1978)]. Correlations of b20, b40, and b60, and of the zero-field splittings, with the ionic radii of the host lanthanides are presented and compared with previous results. Values of the intrinsic parameter ?2 of the superposition model analysis of b20 are obtained for Gd3+ in these salts and are displayed as a function of host ionic radius. The value −3.0 was obtained for the superposition model parameter t2. More detailed analysis of these parameters will require improved knowledge of the rare earth trivalent ion radii and of ion–ligand distances in the ethyl sulfate nonahydrate series.

No abstract

High-precision measured values of g∥ for Gd3+ dilutely substituted in single crystals of 13 lanthanide ethyl sulfate nonahydrates at room temperature (297.3 K) are presented. It is shown that, within the experimental uncertainties, the present observations are entirely accounted for in terms of a model invoking purely magnetic dipolar interactions between the Gd3+ guests and the host structures. On this model, the shift of g∥ depends upon the identity of the lanthanide host, the sample shape, the temperature, and the Gd3+ composition. Moreover, values of the shifts of g∥ at 77.2 K predicted by this model are in agreement, within the experimental uncertainties, with the 77.2 K data of Gerkin and Thorsell [J. Chem. Phys. 57, 2665 (1972)]. Consistent with this model, values of g∥ for spherical samples of 2.0×10−3 mole fraction Gd3+ in 14 of the lanthanide ethyl sulfate nonahydrates at 297.3 K and at 77.2 K are presented.