Effect of chemical pressure on superconductivity of Nd(Sr2-xBax)(Cu2.7Mo 0.3)Oz system

초록

Nd(Sr2-xBax)(Cu2.7Mo0.3)O-z (x = 0-1.0) samples were synthesized and examined with respect to the chemical pressure effect. It is found that the non-superconducting phase NdSr2(Cu2.7Mo0.3)O-z can be made superconducting by substitution Ba at the Sr site. Raman measurements indicate that the movement of the apical oxygen toward the CuO2 planes induced by the chemical pressure is similar to that observed in Y(Ba2-xSrx)Cu3Oz system. Thermoelectric power measurements show that all the samples are underdoped and hole density on the CuO2 planes decreases as the Sr:Ba ratio raised. These results are discussed in relation to the local structural changes induced by the chemical pressure. (C) 2003 Elsevier Science B.V. All rights reserved.

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