Sol–gel synthesis of superconducting YBa2Cu4O8using acetate and tartrate precursors

Abstract
A simple sol–gel route starting from an aqueous mixture of Y, Ba and Cu acetates and tartrates has been refined to prepare superconducting YBa2Cu4O8 at an oxygen pressure of 1 atm. Thermal decomposition of the fabricated gels was studied by means of thermogravimetry. In order to interpret the decomposition mechanisms, both individual and double gels of Y, Ba and Cu were studied. The synthesis products were characterized by X-ray diffraction for phase purity, by thermal analysis for oxygen stability and by SQUID measurements for superconducting properties.