Nanopowders of HoBa2Cu3O7-ä have been prepared by a citrate gel modification of the sol–gel technique atdifferent calcination temperatures, using high-purity nitrate salts of Y, Ba and Cu as starting materials and citric acid as complex agent...

In this paper nanopowders of HoBa2Cu3O7-ä have been prepared by a citrate gel modification of the sol–gel technique. in order to optimize the prepration conditions. the precursor was put under different thermal treatments. In the first thermal...