Crystal structure, electronic, and magnetic properties of the bilayered rhodium oxide Sr3Rh2O7

摘要

The bilayered rhodium oxide Sr3Rh2O7 was synthesized by high-pressure andhigh-temperature heating techniques. The single-phase polycrystalline sample ofSr3Rh2O7 was characterized by measurements of magnetic susceptibility,electrical resistivity, specific heat, and thermopower. The structuralcharacteristics were investigated by powder neutron diffraction study. Therhodium oxide Sr3Rh2O7 [Bbcb, a = 5.4744(8) A, b = 5.4716(9) A, c = 20.875(2)A] is isostructural to the metamagnetic metal Sr3Ru2O7, with five 4d electronsper Rh, which is electronically equivalent to the hypothetic bilayeredruthenium oxide, where one electron per Ru is doped into the Ru-327 unit. Thepresent data show the rhodium oxide Sr3Rh2O7 to be metallic with enhancedparamagnetism, similar to Sr3Ru2O7. However, neither manifest contributionsfrom spin fluctuations nor any traces of a metamagnetic transition were foundwithin the studied range from 2 K to 390 K below 70 kOe.