Specific heat and magnetic susceptibility of the high-Tc superconductor (Bi, Pb, Sb)2Sr2Ca2Cu3O10

Abstract

Abstract The temperature dependence of the specific heat and magnetic susceptibility of single phase (Bi, Pb, Sb) 2 Sr 2 Ca 2 Cu 3 O 10 has been measured. A distinct jump in the specific heat C ( T ) at the superconducting transition temperature T c is obtained with a δ C at T c =6.2±0.2 J/mole K and T c =109 K. This result combined with an estimate of the Sommerfeld constant γ obtained from scaling the temperature independent contribution of the magnetic susceptibility χ( T ) is close to the value of δ C expected assuming a weak coupling BCS theory. The γ-value obtained from δC =1.43 γT c and the temperature independent contribution to χ( T ) is ∼40 mJ/mole K 2 which indicates that the electrons are highly correlated with a band mass ≈10 m 0 where m 0 is the free electron mass. These γ-values and the effective electron mass are very similar to those previously reported for other high- T c superconductors, e.g., YBa 2 Cu 3 O 7 . At low temperatures C ( T ) can be fitted to A / T 2 + γT + βT 3 + C E ( T ) with A =40 mJK/mole, γ⋍0.0 and β =1.76 mJ/mole K 4 and C E ( T ) representing a small Einstein-like contribution to C ( T ) with an Einstein temperature of ∼4 3 K.