Specific heat of Mn-doped NaxCoO2 center dot yH(2)O

Abstract

C(T) of NaxCo0.99Mn0.01O2 center dot yH(2)O is studied to reveal more details on the nature of the doped Mn ions and the T-c suppression. The extra specific heat contribution in NaxCo0.99Mn0.01O2 center dot yH(2)O manifests the induced local magnetic moment due to Mn doping. The absence of the superconducting transition peak in C(T) of NaxCo0.99Mn0.01O2 center dot yH(2)O suggests a reduced superconducting volume fraction. (C) 2007 Elsevier B.V. All rights reserved.