Magnetic Studies of $EuBa₂Cu_{3-x}RuₓO_{7-δ}$ Compounds

Effects of Ru addition on magnetic properties of $EuBa₂Cu_{3-x}RuₓO_{7-δ}$ compounds were studied. Samples of $EuBa₂Cu_{3-x}RuₓO_{7-δ}$ with x from 0.00 to 0.70 were prepared by the solid state reaction technique from Eu₂O₃, BaCO₃, CuO and RuO₂ precursors. Temperature dependences of the zero-field cooled (ZFC) and the field cooled (FC) DC magnetic moment at low and high applied magnetic field Hₐ were measured by the QD SQUID magnetometer MPMS XL-7 and AC magnetization $M_{AC}(H)$ curves at 77 K by the compensation method using the second-order SQUID gradiometer. The molar susceptibility χ of the samples was corrected to the effects of the sample holder and diamagnetism and χ* also was corrected to the temperature independent paramagnetic/diamagnetic contribution $χ^{TN}$ and fitted by the Curie-Weiss relation. The values of the Weiss temperature and the effective magnetic moment have been estimated at low and high value of applied magnetic field.