The temperature-dependent thermoelectric power S of insulating and metallic Bi-2212 and Tl-2212 samples are scaled to universal master curves. For insulating samples, S passes through a peak at a characteristic temperature T * S , which decreases with increasing carrier concentration. For metallic samples a scaling parameter α (= dS/dT at high temperatures) decreases with increasing carrier density. It is argued that T * S is related to the energy needed for activation conduction whereas the change in α may be due to increase in n/m * with carrier density, where n is the concentration and m * is the effective mass of the carriers.
The temperature dependence of the thermoelectric power (TEP) of Bi2Sr,Ca 1 Y Cu&08+y samples are reported for x =0-0.9 in the temperature range 77 -300 K. TEP is positive and large for large x and decreases with decreasing x (increasing carrier concentration). TEP is negative for the x =0 sample.The results are discussed following strong correlation and the Nagaosa and Lee model.
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