Effect of Mn Substitution on the Thermal Expansion of EuBa2Cu3O7–δ

Abstract

Abstract In the present communication, effect of Mn substitution on thermal expansion of EuBa2Cu3–xMnxO7–δ has been investigated. Thermal expansion measurements have been carried out using a high resolution dilatometer based on three terminal capacitance method. The present set–up is sensitive enough to detect small changes in linear thermal expansion coefficient, α of less than 10 –8 per Kelvin. Results show that the pristine sample exhibits a jump in thermal expansion coefficient around its transition temperature which is a characteristic of a second order phase transition.–8 –1For the pure sample a jump in α, of the order of 9.5¥10Khas been observed. It is seen that Mn doping reduces the jump in thermal expansion. Using the well–known Ehrenfest relations, both the pressure dependence of Tc, dTc/dP and the discontinuity in compressibility, ΔK, are determined and are seen to decrease with increase in Mn concentration.