Interlayer CuO 2 antiferromagnetic spin correlations in Tl-based superconducting Tl 2Ba 2Ca nCu n+1 O 6+2 n and Tl 0.5Pb 0.5Sr 2Ca 0.8Y 0.2Cu 2O 7 oxides : 63Cu and 205Tl NMR and spin-lattice relaxation data

Abstract

We analyzed 205Tl and 63Cu spin-lattice relaxation rate data T −1 1 for thallium-based Tl 0.5Pb 0.5Sr 2Ca 0.80Y 0.2 Cu 2O 7 ( T ons c = 107 K) and Tl 2Ba 2Ca n Cu n +1O 6+1 n ( T ons c = 104 K) ( n = 1), T ons c = 125 K ( n = 2)) cuprates which contain one or two TlO layers, respectively. The difference in temperature dependences T −1 1 ( 63Cu) and T −1 1 ( 205Tl) for the one TlO layer compound gives us evidence for the presence of interlayer antiferromagnetic spin correlations between the nearest copper atoms placed in the neighbouring CuO 2 layers.