OVERCOMING THE EFFECT OF CHAIN DISORDER ON THE SEEBECK COEFFICIENT OFESS-THAN-X-LESS-THAN-OR-EQUAL-TO-0.2)(Z)(LN=ND,DY) BY SUBSTITUTION OFCA(0)

We report on the Seebeck coefficient (S) of Ln(1-x)Ca(2)Ba(2)Cu(2.9)Ga (0.1)O(6+z)(Ln=Nd,Dy; 0 less than or equal to x less than or equal to 0.2) as a function of temperature. For Ln=Dy, S at 300 K decreased by a factor of 20 as x(Ca) increased from 0 to 0.2, For all the samples, for a restricted range of temperature, S could be described by S=S-0-a lpha T where S-0, characteristic of each sample, is related to T-c by T-c=82.4-0.64 S-0 and alpha is a constant. (C) 1995 American Institute of Physics.