Magnetic properties of superconducting yttrium barium copper oxide (YBa2Cu3O7-δ) nanoparticles (21 – 30 nm), prepared by a citrate gel modification of the sol-gel technique, have been studied. The nanoparticles have orthorhombic structure.Measuring the magnetic properties showed that they have magnetic properties at room temperature. The development of ferromagnetism is attributed to the presence of surface oxygen vacancies that lead to electron redistribution on the different ions at the surface. So, in on innovative wark, the samples are annealed twice at T= 700 ˚C for 5 h under 0.8 – 0.9 bar of air and then once under oxygen atmosphere at 700 ˚ C for 3h. The M(H) curves of these samples indicated that annealing at vaccum and hten at oxygen improve ferromagnetic properties

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