Separation of magnetic and quadrupolar relaxation rates from spin-lattice recovery laws at short times with illustration in a high-T<sub>c</sub> superconductor
T Rega; T Rega; Dipartimento di Fisica, Pavia Univ., Italy
Журнал:
Journal of Physics: Condensed Matter
Дата:
1991-03-25
Аннотация:
A method to separate the magnetic and quadrupolar rates in the spin-lattice relaxation process for the populations of the levels, without completely solving the master equations, is described. The method can be used, in particular, to evaluate separately the quadrupolar contributions due to the lattice vibrations and the magnetic contribution due to electronic spin dynamics in the <sup>139</sup>La and <sup>63</sup>Cu NQR relaxation in high-T<sub>c</sub> superconductors of the La<sub>2</sub>CuO<sub>4</sub> family. An experimental illustration for the <sup>139</sup>La NQR relaxation measurements in La<sub>2-x</sub>Sr<sub>x</sub>CuO<sub>4</sub> is given.
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