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We have synthesized polycrystalline Sr2IrO4 and measured its magnetic susceptibility, electrical resistivity, specific heat, Seebeck coefficient, and thermal conductivity. The magnetic susceptibility χ(T) shows a ferromagnetic transition at 250 K while the behaviour above the transition temperature is well described by a Curie–Weiss fit with a small effective moment μeff = 0.33 μB and a paramagnetic Curie–Weiss temperature, θCW = +251 K, consistent with previous studies on this compound. However, specific heat, Seebeck coefficient, and thermal conductivity are all dominated by the phonon contribution and show no anomalies at the ferromagnetic transition. Electrical resistivity, unlike the single crystal, shows a huge increase, three orders of magnitude, with decreasing temperature. The temperature dependence of resistivity is logarithmic at high temperatures (210 K

We have investigated the magnetic properties of polycrystalline Y bRu(2)(Ge(1 - x)Si(x))(2) samples using magnetic susceptibility, electrical resistivity, and specific heat measurements. All the results indicate that the Yb ions in Y bRu(2)(Ge(1 - x)Si(x))(2) are in a stable trivalent state. The antiferromagnetic ordering shifts to lower temperature with increasing Si concentration (x). The weak Kondo-like resistivity minimum observed in the resistivity data for x = 0 shifts toward lower temperature with an increase in the Si content and finally disappears. The most dramatic observation is the complete suppression of the quadrupolar ordering in Y bRu(2)Ge(2) (T(Q) = 10 K) even for 2% Si doping.

Superconductivity is found in 50% K-doped EuFe(2)As(2) samples below 33 K. Our results from electrical resistivity, magnetic susceptibility and (57)Fe and (151)Eu Mössbauer spectroscopy provide clear evidence that the ordering of the Fe moments observed at 190 K in undoped EuFe(2)As(2) is completely suppressed in our 50% K-doped sample; thus there is no coexistence of the Fe magnetic order and the superconducting state. However, short range ordering of the Eu moments coexists with the superconducting state below 15 K. A bump in the susceptibility well below T(c) as well as the broadening of the Fe Mössbauer line below 27 K evidence an interplay between the Eu magnetism and the superconducting state.