Ferromagnetic behavior of the Ru sub(1-) sub(x)Sr sub(2GdCu) sub(2)+ sub(xO) sub(8)+/- sub(z system with 0.0~~ZZ: x~~ZZ: 1.0, synthesized at ambient pressure)

• Published in: Physica. C, Superconductivity Vol. 468; no. 21; pp. 2219 - 2223
• Main Authors: Abatal, M, Chavira, E, Filippini, C, Garcia-Vazquez, V, Perez, J C, Tholence, J L
• Format: Journal Article
• Language: English
• Published: 01.10.2008
• Subjects: Air conditioning; Annealing; Differential thermal analysis; Electronics; Ferromagnetism; Pressure; Scanning electron microscopy; Unit cell
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2008.06.006

The Ru sub(1-) sub(x)Sr sub(2GdCu) sub(2)+ sub(xO) sub(8)+/- sub(z system with x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.9 and 1.0 was studied by differential thermal analysis (DTA) in air in order to determine the temperature interval at which the formation of the RuSr) sub(2)GdCu sub(2O) sub(8) (Ru-1212) compound should be formed. For DTA data, samples were prepared by the solid-state reaction method at ambient pressure between 940 degree C and 1050 degree C. From the X-ray powder diffraction (XRD) patterns it was observed that this system is isostructural to the Ru-1212 compound. In addition, a pure phase up to x = 0.4 was obtained. Studies by the Scanning Electron Microscopy (SEM) technique produced a particle size around 1-5 mu m. The results of Transmission Electronic Microscopy (TEM) studies confirm the tetragonal unit cell in the Ru sub(1-) sub(x)Sr sub(2GdCu) sub(2)+ sub(xO) sub(8)+/- sub(z system. The temperature dependence of the electrical resistivity of the samples with x = 0.1, 0.2 and 0.4 annealed in oxygen flux for 6, 12 and 41 h, at T = 960 degree C, shows a semiconducting behavior. The AC magnetic susceptibility measurement indicates ferromagnetic behavior with T) super(C)urie between 130 and 138 K.