Symmetry adapted expressions for the magnetic and quadrupolar nuclear spin-lattice relaxation time T1 in HCP metals are derived from Dirac theory. They are applied systematically to 3d, 4d and 5d metals (Sc, Ti, Y, Zr, Tc, Lu, Hf, Re, Os) on the basis of semi-relativistic and full-relativistic self-consistent LMTO calculations. General trends and relativistic effects are discussed. The relaxation rate T-11 in Zr is overestimated theoretically by a factor of two, as already found by Asada and Terakura. There is strong evidence that the reason for this error lies in spin-orbit splitting. Shifts of 3 mRy in the band position explain the experimental T-11 in Zr. The Fermi surface of Ti is discussed in connection with the theoretical relaxation rate. Some quantities that are useful for the evaluation of measurements like hyperfine coupling constants and ratios between magnetic and quadrupole relaxation rates are presented. Comparison with the experimental data shows that the quadrupole scattering is well reproduced by the theory.
The spin-lattice relaxation rate T1-1 of hexagonal close packed ruthenium has been calculated on the basis of full-relativistic linear muffin tin orbital band structure calculations. For the stable isotopes 99Ru and 101Ru the results are in accord with experiment. The ratio between the theoretical relaxation rates of 101Ru and 99Ru is 1.36. This ratio exhibits, in comparison with the corresponding gamma N2 ratio of 1.26, an additional quadrupole relaxation at 101Ru, which is in line with the large quadrupole moment of 101Ru. Surprisingly, however, the experimental ratio of 1.19 is lower than 1.26. A large discrepancy opens between theory and experiment for the 103Ru relaxation which has been measured by nuclear orientation. Consideration of the dominant quadrupole relaxation rate in the evaluation of the experimental data improves the agreement.
(a), G. KURZ (a), H. WONN (a), V. V. NEMOSHKALENKO (b), and V. N. ANTONOV (b) For the gyromagnetic factor of the conduction electrons in metals a rigorous relativistic theory is developed generalizing Roth's theory, within which the Pauli formalism is used. In a first test calculation the g-shift is calculated for Ag, Au, Pd, and Pt in spherical approximation. The calculations yield a negative g-shift for Ag and a positive g-shift for Au, Pd, and Pt in agreement with the experimental results.
Sektion Physik der Technischen Hochschule Dresden 1) (a) andIn this note the gyromagnetic factor of the conduction electrons for Ag, Au, and several transition metals is studied. The theory was presented in /l/. The results obtained a r e presented in Table 1 .The F e r m i velocity vF and the F e r m i radius qF are determined by the following expressions (in atomic units):N(EF) is the total density of states at the Fermi energy EF, z is an effective charge that is chosen similar as in the theory of conductivity of liquid metals (see Table l), columns in Table 1 correspond to the four terms of the gyromagnetic factor (see (15) of /I/). The ninth column is the total g-factor.no is the volume of the Wigner-Seitz sphere. The fifth to eighthThe first term can be neglected. The third term turns out to be the most important one. Its rigorous expression is given byThe last (surface) term corrects equation (23)
So far it has been supposed that the Hall and drift mobility of the polaron are mainly the same. This supposition was theoretically proved by Schultz' s model of resonance scattering (1). Delves (2), Garcia-Moliner (3),and Langreth (4) calculated the ratio of Hall mobility to drift mobility for small coupling constants ( d < < 1):
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